patch 8.2.3970: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move more errors to errors.h.
diff --git a/src/match.c b/src/match.c
index e0a3017..9589d55 100644
--- a/src/match.c
+++ b/src/match.c
@@ -1403,7 +1403,7 @@
 	    if (*end != NUL && !ends_excmd2(end, skipwhite(end + 1)))
 	    {
 		vim_free(g);
-		eap->errmsg = ex_errmsg(e_trailing_arg, end);
+		eap->errmsg = ex_errmsg(e_trailing_characters_str, end);
 		return;
 	    }
 	    if (*end != *p)