crypto: sa2ul - fix compiler warning produced by clang

Clang detects a warning for an assignment that doesn't really do
anything. Fix this by removing the offending piece of code.

Fixes: 7694b6ca

 ("crypto: sa2ul - Add crypto driver")
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com> # build
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>