fscrypt: don't check for ENOKEY from fscrypt_get_encryption_info()

fscrypt_get_encryption_info() returns 0 if the encryption key is
unavailable; it never returns ENOKEY.  So remove checks for ENOKEY.

Link: https://lore.kernel.org/r/20191209212348.243331-1-ebiggers@kernel.orgSigned-off-by: NEric Biggers <ebiggers@google.com>

fs/ext4/dir.c

@@ -120,7 +120,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
 
 	if (IS_ENCRYPTED(inode)) {
 		err = fscrypt_get_encryption_info(inode);
-		if (err && err != -ENOKEY)
+		if (err)
 			return err;
 	}
 

fs/f2fs/dir.c

@@ -987,7 +987,7 @@ static int f2fs_readdir(struct file *file, struct dir_context *ctx)
 
 	if (IS_ENCRYPTED(inode)) {
 		err = fscrypt_get_encryption_info(inode);
-		if (err && err != -ENOKEY)
+		if (err)
 			goto out;
 
 		err = fscrypt_fname_alloc_buffer(inode, F2FS_NAME_LEN, &fstr);

fs/ubifs/dir.c

@@ -512,7 +512,7 @@ static int ubifs_readdir(struct file *file, struct dir_context *ctx)
 
 	if (encrypted) {
 		err = fscrypt_get_encryption_info(dir);
-		if (err && err != -ENOKEY)
+		if (err)
 			return err;
 
 		err = fscrypt_fname_alloc_buffer(dir, UBIFS_MAX_NLEN, &fstr);