build_examples: Small cleanups

* Override MAKEFLAGS via make not via shell variables
* Remove build_examples in gitlab-ci
* Don't use mktemp for any logs

.gitlab-ci.yml

@@ -142,6 +142,7 @@ build_esp_idf_tests:
   script:
     # it's not possible to build 100% out-of-tree and have the "artifacts"
     # mechanism work, but this is the next best thing
+    - rm -rf build_examples
     - mkdir build_examples
     - cd build_examples
     # build some of examples

tools/ci/build_examples.sh

@@ -44,6 +44,8 @@ die() {
 
 [ -z ${IDF_PATH} ] && die "IDF_PATH is not set"
 
+echo "build_examples running in ${PWD}"
+
 # only 0 or 1 arguments
 [ $# -le 1 ] || die "Have to run as $(basename $0) [<JOB_NAME>]"
 
@@ -55,7 +57,7 @@ RESULT=0
 FAILED_EXAMPLES=""
 
 RESULT_WARNINGS=22  # magic number result code for "warnings found"
-LOG_WARNINGS=$(mktemp -t example_all.XXXX.log)
+LOG_WARNINGS=${PWD}/build_warnings.log
 
 if [ $# -eq 0 ]
 then
@@ -114,7 +116,7 @@ build_example () {
         # build non-verbose first
         local BUILDLOG=${PWD}/examplebuild.${ID}.log
         (
-            MAKEFLAGS= make clean defconfig &> >(tee -a "${BUILDLOG}") &&
+            make MAKEFLAGS= clean defconfig &> >(tee -a "${BUILDLOG}") &&
             make all &> >(tee -a "${BUILDLOG}")
         ) || {
             RESULT=$?; FAILED_EXAMPLES+=" ${EXAMPLE_NAME}"