makefile: Drop semicolons in 'go build' output to not confuse vim

When running "make" under vim, it treats numbers after semicolons as
line numbers and the existing invocation of "git lot" uses the date format
with semicolons.

This changes the git rev not to use semicolons so it changes from
"Wed, 13 May 2020 21:11:52 +0200" to "20200513-211152".

Signed-off-by: Alexey Kardashevskiy <aik@linux.ibm.com>

Makefile

@@ -59,7 +59,7 @@ ifeq ("$(shell git diff --shortstat)", "")
 else
 	REV=$(GITREV)+
 endif
-GITREVDATE=$(shell git log -n 1 --format="%ad")
+GITREVDATE=$(shell git log -n 1 --format="%ad" --date=format:%Y%m%d-%H%M%S)
 
 # Don't generate symbol table and DWARF debug info.
 # Reduces build time and binary sizes considerably.

prog/meta.go

@@ -19,7 +19,7 @@ func init() {
 	GitRevisionBase = strings.Replace(GitRevision, "+", "", -1)
 	if gitRevisionDate != "" {
 		var err error
-		if GitRevisionDate, err = time.Parse("Mon Jan 2 15:04:05 2006 -0700", gitRevisionDate); err != nil {
+		if GitRevisionDate, err = time.Parse("20060102-150405", gitRevisionDate); err != nil {
 			panic(err)
 		}
 	}