alias.c: mark split_cmdline_strerror() strings for translation

This function can be part of translated messages. To make sure we
don't have a sentence with mixed languages, mark the strings for
translation, but only use translated strings in places we know we will
output translated strings.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/alias.c b/alias.c
index a7e4e57..c471538 100644
--- a/alias.c
+++ b/alias.c
@@ -47,8 +47,8 @@ void list_aliases(struct string_list *list)
 #define SPLIT_CMDLINE_BAD_ENDING 1
 #define SPLIT_CMDLINE_UNCLOSED_QUOTE 2
 static const char *split_cmdline_errors[] = {
-	"cmdline ends with \\",
-	"unclosed quote"
+	N_("cmdline ends with \\"),
+	N_("unclosed quote")
 };
 
 int split_cmdline(char *cmdline, const char ***argv)