ceph: fix dout() compile warnings in ceph_filemap_fault()
ceph: fix dout() compile warnings in ceph_filemap_fault()

PAGE_CACHE_SIZE is unsigned long on all architectures, however size_t
is either unsigned int or unsigned long.  Rather than change format
strings, cast PAGE_CACHE_SIZE to size_t to be in line with dout()s in
ceph_page_mkwrite().

Cc: Yan, Zheng <45e2ee8c8b09e76a9d512320d4eb53c0cd9925c0@intel.com>
Signed-off-by: Ilya Dryomov <33f1a10eef0a3354755a1541edfdb100ff87fcfc@inktank.com>
Reviewed-by: Sage Weil <6dd34506bbd5e58221bbb3e4732d97c91f02277b@inktank.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs