ocfs2: add freeze protection to ocfs2_file_splice_write()

ocfs2: add freeze protection to ocfs2_file_splice_write()

ocfs2_file_splice_write() was missed when adding freeze protection to all
write paths. Fix that.

Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
Cc: Marco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>