patch 8.0.1702: leaking memory when autocommands make quickfix list invalid

Problem:    Leaking memory when autocommands make a quickfix list invalid.
Solution:   Call FreeWild(). (Yegappan Lakshmanan)
diff --git a/src/quickfix.c b/src/quickfix.c
index 8c1df17..c370761 100644
--- a/src/quickfix.c
+++ b/src/quickfix.c
@@ -4556,7 +4556,10 @@
 	/* Check whether the quickfix list is still valid. When loading a
 	 * buffer above, autocommands might have changed the quickfix list. */
 	if (!vgr_qflist_valid(wp, qi, save_qfid, *eap->cmdlinep))
+	{
+	    FreeWild(fcount, fnames);
 	    goto theend;
+	}
 	save_qfid = qi->qf_lists[qi->qf_curlist].qf_id;
 
 	if (buf == NULL)