Port is allocated by sas_port_alloc_num() and rphy is allocated by either
sas_end_device_alloc() or sas_expander_alloc(), all of which may return
NULL. So we need to check the rphy to avoid possible NULL pointer access.

If sas_rphy_add() returned with failure, rphy is set to NULL. We would
access the rphy in the following lines which would also result NULL pointer
access.

Fixes: 78316e9d ("scsi: mpt3sas: Fix possible resource leaks in mpt3sas_transport_port_add()")
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20230225100135.2109330-1-haowenchao2@huawei.comAcked-by: Sathya Prakash Veerichetty <sathya.prakash@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>