iov_iter: Make count and size loff_t not size_t

Make count and offset loff_t not size_t so that they can handle I/O
transactions larger than 4GiB in size and starting at more than 4GiB into a
file on a 32-bit system.

On a 64-bit system, this should make no difference.

Signed-off-by: David Howells <dhowells@redhat.com>
7 files changed