mtip_pci_probe() dumps the current CPU when loaded, but it does
so in a preemptible context. Hence smp_processor_id() correctly
warns:

BUG: using smp_processor_id() in preemptible [00000000] code: systemd-udevd/155
caller is mtip_pci_probe+0x53/0x880 [mtip32xx]

Switch to raw_smp_processor_id(), since it's just informational
and persistent accuracy isn't important.
Signed-off-by: Jens Axboe <axboe@fb.com>