scsi: mpi3mr: Use scnprintf() instead of snprintf()

I intended to move from snprintf() to scnprintf() in the previous patch but
I messed up and did not do that.  The result of my bug is that it this
function could trigger a WARN() if the buffer is too large.

Link: https://lore.kernel.org/r/20211013083005.GA8592@kili
Fixes: 76a4f7cc

 ("scsi: mpi3mr: Clean up mpi3mr_print_ioc_info()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>