tag, update-ref: improve description of option "create-reflog"

The description of option "create-reflog" is "create_reflog", which
is neither a good description, nor a sensible string to translate.
Change it to a more meaningful message.

Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/tag.c

@@ -606,7 +606,7 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
 		OPT_STRING('u', "local-user", &keyid, N_("key-id"),
 					N_("use another key to sign the tag")),
 		OPT__FORCE(&force, N_("replace the tag if exists")),
-		OPT_BOOL(0, "create-reflog", &create_reflog, N_("create_reflog")),
+		OPT_BOOL(0, "create-reflog", &create_reflog, N_("create a reflog")),
 
 		OPT_GROUP(N_("Tag listing options")),
 		OPT_COLUMN(0, "column", &colopts, N_("show tag list in columns")),

builtin/update-ref.c

@@ -365,7 +365,7 @@ int cmd_update_ref(int argc, const char **argv, const char *prefix)
 					N_("update <refname> not the one it points to")),
 		OPT_BOOL('z', NULL, &end_null, N_("stdin has NUL-terminated arguments")),
 		OPT_BOOL( 0 , "stdin", &read_stdin, N_("read updates from stdin")),
-		OPT_BOOL( 0 , "create-reflog", &create_reflog, N_("create_reflog")),
+		OPT_BOOL( 0 , "create-reflog", &create_reflog, N_("create a reflog")),
 		OPT_END(),
 	};