Fixed building with backported AppArmor

mm/util.c

@@ -479,6 +479,15 @@ unsigned long vm_mmap(struct file *file, unsigned long addr,
 }
 EXPORT_SYMBOL(vm_mmap);
 
+void kvfree(const void *addr)
+{
+	if (is_vmalloc_addr(addr))
+		vfree(addr);
+	else
+		kfree(addr);
+}
+EXPORT_SYMBOL(kvfree);
+
 struct address_space *page_mapping(struct page *page)
 {
 	struct address_space *mapping = page->mapping;