Teach git-submodule.sh about the .git file

When git-submodule tries to detect 'active' submodules, it checks for the
existence of a directory named '.git'. This isn't good enough now that .git
can be a file pointing to the real $GIT_DIR so the tests are changed to
reflect this.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: hjemli

git-submodule.sh

@@ -300,7 +300,7 @@ cmd_update()
 			continue
 		fi
 
-		if ! test -d "$path"/.git
+		if ! test -d "$path"/.git -o -f "$path"/.git
 		then
 			module_clone "$path" "$url" || exit
 			subsha1=
@@ -542,7 +542,7 @@ cmd_status()
 	do
 		name=$(module_name "$path") || exit
 		url=$(git config submodule."$name".url)
-		if test -z "$url" || ! test -d "$path"/.git
+		if test -z "$url" || ! test -d "$path"/.git -o -f "$path"/.git
 		then
 			say "-$sha1 $path"
 			continue;