[SCSI] ipr: ipr_remove() marked __devexit

Marking the ipr clean up function ipr_remove() as __devexit and using
__devexit_p() macro in its address reference.

Signed-off-by: Kleber Sacilotto de Souza <kleber@linux.vnet.ibm.com>
Reported-by: Breno Leitao <leitao@linux.vnet.ibm.com>
Acked-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>