block/iscsi.c: Fix printf format error.

block/iscsi.c: Fix printf format error.

The error on armv7hl was:

block/iscsi.c: In function ‘is_request_lun_aligned’:
block/iscsi.c:251:26: error: format ‘%ld’ expects argument of type ‘long int’, but argument 3 has type ‘int64_t’ [-Werror=format=]
                          iscsilun->block_size, sector_num, nb_sectors);
                          ^

This also splits the long line to comply with qemu coding guidelines.

Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>