build fixed when simpler shells are used to create release.h

mkreleasehdr.sh

 #!/bin/sh
-GIT_SHA1=$((git show-ref --head --hash=8 2> /dev/null || echo 00000000) | head -n1)
+GIT_SHA1=$(git show-ref --head --hash=8 2> /dev/null | head -n1)
 GIT_DIRTY=$(git diff 2> /dev/null | wc -l)
 test -f release.h || touch release.h
 (cat release.h | grep SHA1 | grep $GIT_SHA1) && \
 (cat release.h | grep DIRTY | grep $GIT_DIRTY) && exit 0 # Already uptodate
 echo "#define REDIS_GIT_SHA1 \"$GIT_SHA1\"" > release.h
-echo "#define REDIS_GIT_DIRTY $GIT_DIRTY" >> release.h
+echo "#define REDIS_GIT_DIRTY \"$GIT_DIRTY\"" >> release.h
 touch redis.c # force recompile of redis.c

redis.c

@@ -7203,7 +7203,7 @@ static sds genRedisInfoString(void) {
         "role:%s\r\n"
         ,REDIS_VERSION,
         REDIS_GIT_SHA1,
-        REDIS_GIT_DIRTY > 0,
+        strtol(REDIS_GIT_DIRTY,NULL,10) > 0,
         (sizeof(long) == 8) ? "64" : "32",
         aeGetApiName(),
         (long) getpid(),