target: fix NULL pointer dereference bug alloc_page() fails to get memory
I am hitting this bug when the target is low in memory that fails the
alloc_page() for the newly submitted command. This is a sort of off-by-one
bug causing NULL pointer dereference in __free_page() since 'i' here is
really the counter of total pages that have been successfully allocated here.
Signed-off-by: Yi Zou <yi.zou@intel.com> Cc: Andy Grover <agrover@redhat.com> Cc: Nicholas Bellinger <nab@linux-iscsi.org> Cc: Open-FCoE.org <devel@open-fcoe.org> Cc: stable@vger.kernel.org Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>