make nr_pages calculation in default_file_splice_read() a bit less ugly

It's an artifact of lousy calling conventions of iov_iter_get_pages_alloc().
Hopefully, we'll get something saner come next cycle; for now that'll
do.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2016-12-10 13:20:53 -05:00
commit 13c0f52beb