patch 8.1.1962: leaking memory when using tagfunc()

Problem:    Leaking memory when using tagfunc().
Solution:   Free the user_data. (Dominique Pelle, closes #4886)

src/version.c

@@ -761,6 +761,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1962,
 /**/
     1961,
 /**/

src/window.c

@@ -4892,8 +4892,10 @@ win_free(
     win_free_lsize(wp);
 
     for (i = 0; i < wp->w_tagstacklen; ++i)
+    {
 	vim_free(wp->w_tagstack[i].tagname);
-
+	vim_free(wp->w_tagstack[i].user_data);
+    }
     vim_free(wp->w_localdir);
 
     /* Remove the window from the b_wininfo lists, it may happen that the