scsi: ufs: ice: propagate memeory allocation failure error

It is possible that ice workqueue allocation fails in cases like
low memory or other workqueue allocation failures. Propagate proper
error code up in call stack for effective error handling by system. Also
check if ice workqueue is allocated before scheduling it to avoid possible
NULL pointer dereference.

Change-Id: I5aec3c20b31d6c3a78f7389b6df26fad2ebfb041
Signed-off-by: Neeraj Soni <neersoni@codeaurora.org>