setup.c: fix comment about order of .git directory discovery

Since gitfiles were introduced in b44ebb19e (Add platform-independent
.git "symlink", 2008-02-20) the order of checks during .git directory
discovery is: gitfile, gitdir, bare repo.  However, that commit did
only partially update the in-code comment describing this order,
missing the last line which still puts gitdir before gitfile.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

setup.c

@@ -882,7 +882,7 @@ static const char *setup_git_directory_gently_1(int *nongit_ok)
 	 * - ../.git
 	 * - ../.git/
 	 * - ../ (bare)
-	 * - ../../.git/
+	 * - ../../.git
 	 *   etc.
 	 */
 	one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);