pcr0tool: Minor improvements

* List commands alphabetically.
* Use log.Fatalf instead of panic

cmd/pcr0tool/commands/pcrread/command.go

@@ -71,7 +71,7 @@ func (cmd Command) Execute(ctx context.Context, args []string) {
 		}
 	}
 	if hashAlgo == tpm2.AlgUnknown {
-		panic(fmt.Errorf("algo '%s' is unknown", *cmd.hashAlgo))
+		log.Fatalf("algo '%s' is unknown", *cmd.hashAlgo)
 	}
 	pcr, err := tpm.ReadPCRFromTPM(pcr.ID(pcrIndex), hashAlgo)
 	assertNoError(err)

cmd/pcr0tool/main.go

@@ -32,9 +32,9 @@ var knownCommands = map[string]commands.Command{
 	"display_fwinfo":               &displayfwinfo.Command{},
 	"dump_fit":                     &dumpfit.Command{},
 	"dump_registers":               &dumpregisters.Command{},
+	"pcrread":                      &pcrread.Command{},
 	"printnodes":                   &printnodes.Command{},
 	"validate_security":            &validatesecurity.Command{},
-	"pcrread":                      &pcrread.Command{},
 	"sum":                          &sum.Command{},
 }