f2fs crypto: do not set encryption policy for non-directory by ioctl

Encryption policy should only be set to an empty directory through ioctl,
This patch add a judgement condition to verify type of the target inode
to avoid incorrectly configuring for non-directory.

Additionally, remove unneeded inline data conversion since regular or symlink
file should not be processed here.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/crypto_policy.c b/fs/f2fs/crypto_policy.c
index 30b0b73..d4a96af 100644
--- a/fs/f2fs/crypto_policy.c
+++ b/fs/f2fs/crypto_policy.c
@@ -92,6 +92,9 @@
 	if (policy->version != 0)
 		return -EINVAL;
 
+	if (!S_ISDIR(inode->i_mode))
+		return -EINVAL;
+
 	if (!f2fs_inode_has_encryption_context(inode)) {
 		if (!f2fs_empty_dir(inode))
 			return -ENOTEMPTY;