vim-patch:8.2.0544: memory leak in search test

Problem:    Memory leak in search test.
Solution:   Free msgbuf. (Dominique Pelle, closes vim/vim#5912)
880e4d9117

src/nvim/search.c

@@ -1192,6 +1192,7 @@ int do_search(
         len = STRLEN(p) + off_len + 3;
       }
 
+      xfree(msgbuf);
       msgbuf = xmalloc(len);
       {
         memset(msgbuf, ' ', len);