scsi: lpfc: add check for loss of ndlp when sending RRQ

There was a missing qualification of a valid ndlp structure when calling to
send an RRQ for an abort.  Add the check.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>