[SCSI] sd: Switch kernel printing level for DIF messages

For some reason these messages ended up being printed with KERN_INFO
rendering them invisible to pretty much everyone.  Switch to
KERN_NOTICE.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>