menuconfig: Fix memory leak introduced by jump keys feature

Fixes the memory leak of struct jump_key allocated in get_prompt_str()

Signed-off-by: Benjamin Poirier <bpoirier@suse.de>
Tested-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: stable@vger.kernel.org

scripts/kconfig/list.h

@@ -50,6 +50,19 @@ struct list_head {
 	     &pos->member != (head); 	\
 	     pos = list_entry(pos->member.next, typeof(*pos), member))
 
+/**
+ * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
+ * @pos:	the type * to use as a loop cursor.
+ * @n:		another type * to use as temporary storage
+ * @head:	the head for your list.
+ * @member:	the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_safe(pos, n, head, member)			\
+	for (pos = list_entry((head)->next, typeof(*pos), member),	\
+		n = list_entry(pos->member.next, typeof(*pos), member);	\
+	     &pos->member != (head);					\
+	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
+
 /**
  * list_empty - tests whether a list is empty
  * @head: the list to test.

scripts/kconfig/mconf.c

@@ -389,6 +389,7 @@ again:
 			.targets = targets,
 			.keys = keys,
 		};
+		struct jump_key *pos, *tmp;
 
 		res = get_relations_str(sym_arr, &head);
 		dres = show_textbox_ext(_("Search Results"), (char *)
@@ -402,6 +403,8 @@ again:
 				again = true;
 			}
 		str_free(&res);
+		list_for_each_entry_safe(pos, tmp, &head, entries)
+			free(pos);
 	} while (again);
 	free(sym_arr);
 	str_free(&title);