f2fs crypto: check encryption for tmpfile

This patch adds to check encryption for tmpfile in early stage.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/namei.c

@@ -569,6 +569,12 @@ static int __f2fs_tmpfile(struct inode *dir, struct dentry *dentry,
 
 static int f2fs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
 {
+	if (f2fs_encrypted_inode(dir)) {
+		int err = f2fs_get_encryption_info(dir);
+		if (err)
+			return err;
+	}
+
 	return __f2fs_tmpfile(dir, dentry, mode, NULL);
 }