crypto: msm: Fix kernel crash due to use of sg_next

sg_next() may find wrong scatter-gather buffer in crypto subsystem,
and this causes a kernel crash. scatterwalk_sg_next() should be used
instead in crypto related drivers.

Change-Id: Ia8b87a91165e915d3b0709331a83e3b40bd02493
Signed-off-by: Mona Hossain <mhossain@codeaurora.org>