shmem: make use of ->free_inode()

same situation as for hugetlbfs
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

mm/shmem.c

@@ -3635,9 +3635,8 @@ static struct inode *shmem_alloc_inode(struct super_block *sb)
 	return &info->vfs_inode;
 }
 
-static void shmem_destroy_callback(struct rcu_head *head)
+static void shmem_free_in_core_inode(struct inode *inode)
 {
-	struct inode *inode = container_of(head, struct inode, i_rcu);
 	if (S_ISLNK(inode->i_mode))
 		kfree(inode->i_link);
 	kmem_cache_free(shmem_inode_cachep, SHMEM_I(inode));
@@ -3647,7 +3646,6 @@ static void shmem_destroy_inode(struct inode *inode)
 {
 	if (S_ISREG(inode->i_mode))
 		mpol_free_shared_policy(&SHMEM_I(inode)->policy);
-	call_rcu(&inode->i_rcu, shmem_destroy_callback);
 }
 
 static void shmem_init_inode(void *foo)
@@ -3738,6 +3736,7 @@ static const struct inode_operations shmem_special_inode_operations = {
 
 static const struct super_operations shmem_ops = {
 	.alloc_inode	= shmem_alloc_inode,
+	.free_inode	= shmem_free_in_core_inode,
 	.destroy_inode	= shmem_destroy_inode,
 #ifdef CONFIG_TMPFS
 	.statfs		= shmem_statfs,