Performing an LS abort results in the following message being seen:
  0603 Invalid CQ subtype 6: 00000300 22000002 ffff0016 d0050000
and the associated exchange is not properly freed.

The code did not recognize the exchange type that was aborted, thus it
was not properly handled.

Correct by adding the NVME LS ELS type to the exchange types that are
recognized.
Signed-off-by: NDick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: NJames Smart <james.smart@broadcom.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>