Merge branch 'chcr-Fixing-issues-in-dma-mapping-and-driver-removal'

Ayush Sawal says:

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Fixing issues in dma mapping and driver removal

Patch 1: This fixes the kernel panic which occurs due to the accessing
of a zero length sg.

Patch 2: Avoiding unregistering the algorithm if cra_refcnt is not 1.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>