builtin/clone.c: trivial fix of message

bare in that context is an option, not purely an adjective
Mark it properly

Signed-off-by: Alexander Shopov <ash@kambanaria.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/clone.c b/builtin/clone.c
index 315befa..f0261bb 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -115,7 +115,7 @@ static struct option builtin_clone_options[] = {
 	OPT_HIDDEN_BOOL(0, "naked", &option_bare,
 			N_("create a bare repository")),
 	OPT_BOOL(0, "mirror", &option_mirror,
-		 N_("create a mirror repository (implies bare)")),
+		 N_("create a mirror repository (implies --bare)")),
 	OPT_BOOL('l', "local", &option_local,
 		N_("to clone from a local repository")),
 	OPT_BOOL(0, "no-hardlinks", &option_no_hardlinks,