vim-patch:9.2.0106: memory leak in expand_findfunc()

Problem:  memory leak in expand_findfunc() (after v9.1.0811)
Solution: Free list variable l on early return (Huihui Huang).

closes: vim/vim#19564

https://github.com/vim/vim/commit/648240fe9a0013354a0a15777d0d5c8eb203df3d

N/A patches:
vim-patch:9.2.0105: memory leak in heredoc_get() in src/evalvars.c

Co-authored-by: Huihui Huang <625173@qq.com>

src/nvim/ex_docmd.c

@@ -5463,6 +5463,7 @@ int expand_findfunc(char *pat, char ***files, int *numMatches)
 
   int len = tv_list_len(l);
   if (len == 0) {  // empty List
+    tv_list_free(l);
     return FAIL;
   }