hashtable: remove caps buffer

slre_match() checks if caps == NULL. In this case it does not try to
update it. So there is no need to create a buffer caps which we do not
evaluate.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/lib/hashtable.c b/lib/hashtable.c
index 93028ed..50ff40a 100644
--- a/lib/hashtable.c
+++ b/lib/hashtable.c
@@ -542,9 +542,8 @@
 	case H_MATCH_REGEX:
 		{
 			struct slre *slrep = (struct slre *)priv;
-			struct cap caps[slrep->num_caps + 2];
 
-			if (slre_match(slrep, str, strlen(str), caps))
+			if (slre_match(slrep, str, strlen(str), NULL))
 				return 1;
 		}
 		break;