integrity: fix IMA inode leak

CONFIG_IMA=y inode activity leaks iint_cache and radix_tree_node objects
until the system runs out of memory.  Nowhere is calling ima_inode_free()
a.k.a. ima_iint_delete().  Fix that by calling it from destroy_inode().
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/inode.c

@@ -219,6 +219,7 @@ static struct inode *alloc_inode(struct super_block *sb)
 void destroy_inode(struct inode *inode)
 {
 	BUG_ON(inode_has_buffers(inode));
+	ima_inode_free(inode);
 	security_inode_free(inode);
 	if (inode->i_sb->s_op->destroy_inode)
 		inode->i_sb->s_op->destroy_inode(inode);