nfs4: The difference of 2 pointers is ptrdiff_t

nfs4: The difference of 2 pointers is ptrdiff_t

On m68k, which is 32-bit:

fs/nfs/nfs4proc.c: In function ‘nfs41_sequence_done’:
fs/nfs/nfs4proc.c:432: warning: format ‘%ld’ expects type ‘long int’, but argument 3 has type ‘int’
fs/nfs/nfs4proc.c: In function ‘nfs4_setup_sequence’:
fs/nfs/nfs4proc.c:576: warning: format ‘%ld’ expects type ‘long int’, but argument 5 has type ‘int’

On 32-bit, ptrdiff_t is int; on 64-bit, ptrdiff_t is long.

Introduced by commit 035593fb77277031a31e8c64b6ce83b439008e3c ("NFSv4.1: keep
seq_res.sr_slot as pointer rather than an index")

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>