mm, memory_hotplug: update a comment in unregister_memory()

The remove_memory_block() function was renamed to in commit
cc292b0b ("drivers/base/memory.c: rename remove_memory_block() to
remove_memory_section()").
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/memory.c

@@ -732,7 +732,7 @@ unregister_memory(struct memory_block *memory)
 {
 	BUG_ON(memory->dev.bus != &memory_subsys);
 
-	/* drop the ref. we got in remove_memory_block() */
+	/* drop the ref. we got in remove_memory_section() */
 	put_device(&memory->dev);
 	device_unregister(&memory->dev);
 }