RDMA/srp: Fix srp_abort()

Fix the code for converting a SCSI command pointer into an SRP request
pointer.

Cc: Xiao Yang <yangx.jy@fujitsu.com>
Fixes: ad215aae ("RDMA/srp: Make struct scsi_cmnd and struct srp_request adjacent")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220908233139.3042628-1-bvanassche@acm.org


Signed-off-by: Leon Romanovsky <leon@kernel.org>