[SCSI] qla2xxx: Add test for valid loop id to qla2x00_relogin().

If fabric device has invalid loop id (FC_NO_LOOP_ID) then call
qla2x00_find_new_loop_id() to attempt to obtain valid loop id.

Signed-off-by: Joe Carnuccio <joe.carnuccio@qlogic.com>
Signed-off-by: Madhuranath Iyengar <Madhu.Iyengar@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>