Revert "fs: check FMODE_LSEEK to control internal pipe splicing"

This reverts commit fd0a6e9.

Which was upstream commit 97ef77c.

The commit is missing dependencies and breaks NFS tests, remove it for
now.

Reported-by: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

fs/splice.c

@@ -895,15 +895,17 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd,
 {
 	struct pipe_inode_info *pipe;
 	long ret, bytes;
+	umode_t i_mode;
 	size_t len;
 	int i, flags, more;
 
 	/*
-	 * We require the input to be seekable, as we don't want to randomly
-	 * drop data for eg socket -> socket splicing. Use the piped splicing
-	 * for that!
+	 * We require the input being a regular file, as we don't want to
+	 * randomly drop data for eg socket -> socket splicing. Use the
+	 * piped splicing for that!
 	 */
-	if (unlikely(!(in->f_mode & FMODE_LSEEK)))
+	i_mode = file_inode(in)->i_mode;
+	if (unlikely(!S_ISREG(i_mode) && !S_ISBLK(i_mode)))
 		return -EINVAL;
 
 	/*