crypto: x86/sha256-mb - fix panic due to unaligned access

struct sha256_ctx_mgr allocated in sha256_mb_mod_init() via kzalloc()
and later passed in sha256_mb_flusher_mgr_flush_avx2() function where
instructions vmovdqa used to access the struct. vmovdqa requires
16-bytes aligned argument, but nothing guarantees that struct
sha256_ctx_mgr will have that alignment. Unaligned vmovdqa will
generate GP fault.

Fix this by replacing vmovdqa with vmovdqu which doesn't have alignment
requirements.

Fixes: a377c6b1

 ("crypto: sha256-mb - submit/flush routines for AVX2")
Reported-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: <stable@vger.kernel.org>
Acked-by: Tim Chen
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>