Fix some nonsense came from LGTM (#9962)

1. Local variable 's' hides a parameter of the same name.
```
int anetTcpAccept(char *err, int s, char *ip, size_t ip_len, int *port) {
    if ((fd = anetGenericAccept(err,s,(struct sockaddr*)&sa,&salen)) == ANET_ERR){}
}
```
Change the parameter name from `s` to `serversock`,
also unified with the header file definition.

2. Comparison is always false because i <= 48.
```
for (i = 0; i < DICT_STATS_VECTLEN-1; i++) {  // i < 49
    (i == DICT_STATS_VECTLEN-1)?">= ":"",  // i == 49
}
```
`i == DICT_STATS_VECTLEN-1` always result false, it is a dead code.

3. Empty block without comment.
`else if (!strcasecmp(opt,"ch")) {}`, add a comment to avoid warnings.

4. Bit field fill of type int should have explicitly unsigned integral, explicitly signed integral, or enumeration type.
Modify `int fill: QL_FILL_BITS;` to `unsigned int fill: QL_FILL_BITS;`

5. The result of this call to reconnectingRedisCommand is not checked for null, but 80% of calls to reconnectingRedisCommand check for null.
Just a cleanup job like others.

src/anet.c

@@ -529,11 +529,11 @@ static int anetGenericAccept(char *err, int s, struct sockaddr *sa, socklen_t *l
 
 /* Accept a connection and also make sure the socket is non-blocking, and CLOEXEC.
  * returns the new socket FD, or -1 on error. */
-int anetTcpAccept(char *err, int s, char *ip, size_t ip_len, int *port) {
+int anetTcpAccept(char *err, int serversock, char *ip, size_t ip_len, int *port) {
     int fd;
     struct sockaddr_storage sa;
     socklen_t salen = sizeof(sa);
-    if ((fd = anetGenericAccept(err,s,(struct sockaddr*)&sa,&salen)) == ANET_ERR)
+    if ((fd = anetGenericAccept(err,serversock,(struct sockaddr*)&sa,&salen)) == ANET_ERR)
         return ANET_ERR;
 
     if (sa.ss_family == AF_INET) {

src/dict.c

@@ -1154,8 +1154,7 @@ size_t _dictGetStatsHt(char *buf, size_t bufsize, dict *d, int htidx) {
         if (clvector[i] == 0) continue;
         if (l >= bufsize) break;
         l += snprintf(buf+l,bufsize-l,
-            "   %s%ld: %ld (%.02f%%)\n",
-            (i == DICT_STATS_VECTLEN-1)?">= ":"",
+            "   %ld: %ld (%.02f%%)\n",
             i, clvector[i], ((float)clvector[i]/DICTHT_SIZE(d->ht_size_exp[htidx]))*100);
     }
 

src/geo.c

@@ -444,7 +444,7 @@ void geoaddCommand(client *c) {
         char *opt = c->argv[longidx]->ptr;
         if (!strcasecmp(opt,"nx")) nx = 1;
         else if (!strcasecmp(opt,"xx")) xx = 1;
-        else if (!strcasecmp(opt,"ch")) {}
+        else if (!strcasecmp(opt,"ch")) { /* Handle in zaddCommand. */ }
         else break;
         longidx++;
     }

src/quicklist.h

@@ -107,7 +107,7 @@ typedef struct quicklist {
     quicklistNode *tail;
     unsigned long count;        /* total count of all entries in all listpacks */
     unsigned long len;          /* number of quicklistNodes */
-    int fill : QL_FILL_BITS;              /* fill factor for individual nodes */
+    unsigned int fill : QL_FILL_BITS;     /* fill factor for individual nodes */
     unsigned int compress : QL_COMP_BITS; /* depth of end nodes not to compress;0=off */
     unsigned int bookmark_count: QL_BM_BITS;
     quicklistBookmark bookmarks[];

src/redis-cli.c

@@ -7904,8 +7904,11 @@ static void statMode(void) {
         int j;
 
         reply = reconnectingRedisCommand(context,"INFO");
-        if (reply->type == REDIS_REPLY_ERROR) {
-            printf("ERROR: %s\n", reply->str);
+        if (reply == NULL) {
+            fprintf(stderr, "\nI/O error\n");
+            exit(1);
+        } else if (reply->type == REDIS_REPLY_ERROR) {
+            fprintf(stderr, "ERROR: %s\n", reply->str);
             exit(1);
         }
 
@@ -8071,7 +8074,7 @@ static void LRUTestMode(void) {
                 if (redisGetReply(context, (void**)&reply) == REDIS_OK) {
                     switch(reply->type) {
                         case REDIS_REPLY_ERROR:
-                            printf("%s\n", reply->str);
+                            fprintf(stderr, "%s\n", reply->str);
                             break;
                         case REDIS_REPLY_NIL:
                             misses++;