patch 8.2.4084: memory leak when looking for autoload prefixed variable

Problem:    Memory leak when looking for autoload prefixed variable.
Solution:   Free the concatenated string.

src/evalvars.c

@@ -2889,14 +2889,14 @@ find_var(char_u *name, hashtab_T **htp, int no_autoload)
 	    {
 		ht = &globvarht;
 		ret = find_var_in_ht(ht, *name, auto_name, TRUE);
+		vim_free(auto_name);
 		if (ret != NULL)
 		{
 		    if (htp != NULL)
 			*htp = ht;
 		    return ret;
 		}
 	    }
-	    vim_free(auto_name);
 	}
     }
 

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4084,
 /**/
     4083,
 /**/