scripts: check if .git exists before checking submodule status

Currently we check status of each submodule, before actually checking
if we're in a git repo. These status commands will all fail, but we
are hiding their output so we don't see it currently.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

scripts/git-submodule.sh

@@ -51,6 +51,12 @@ validate_error() {
     exit 1
 }
 
+if test -n "$maybe_modules" && ! test -e ".git"
+then
+    echo "$0: unexpectedly called with submodules but no git checkout exists"
+    exit 1
+fi
+
 modules=""
 for m in $maybe_modules
 do
@@ -63,12 +69,6 @@ do
     fi
 done
 
-if test -n "$maybe_modules" && ! test -e ".git"
-then
-    echo "$0: unexpectedly called with submodules but no git checkout exists"
-    exit 1
-fi
-
 case "$command" in
 status|validate)
     if test -z "$maybe_modules"