scsi: qla2xxx: Avoid fcport pointer dereference

In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Avoid fcport pointer dereference Klocwork reported warning of NULL pointer may be dereferenced. The routine exits when sa_ctl is NULL and fcport is allocated after the exit call thus causing NULL fcport pointer to dereference at the time of exit. To avoid fcport pointer dereference, exit the routine when sa_ctl is NULL.