ecryptfs: lookup: Don't check if mount_crypt_stat is NULL

mount_crypt_stat is assigned to
&ecryptfs_superblock_to_private(ecryptfs_dentry->d_sb)->mount_crypt_stat,
and mount_crypt_stat is not the first object in struct ecryptfs_sb_info.
mount_crypt_stat is therefore never NULL. At the same time, no crash
in ecryptfs_lookup() has been reported, and the lookup functions in
other file systems don't check if d_sb is NULL either.
Given that, remove the NULL check.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>

fs/ecryptfs/inode.c

@@ -395,8 +395,7 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
 
 	mount_crypt_stat = &ecryptfs_superblock_to_private(
 				ecryptfs_dentry->d_sb)->mount_crypt_stat;
-	if (mount_crypt_stat
-	    && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)) {
+	if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
 		rc = ecryptfs_encrypt_and_encode_filename(
 			&encrypted_and_encoded_name, &len,
 			mount_crypt_stat, name, len);