Revert "crypto: shash - avoid comparing pointers to exported functions under CFI"

This reverts commit 22ca9f4a because CFI
no longer breaks cross-module function address equality, so
crypto_shash_alg_has_setkey() can now be an inline function like before.

This commit should not be backported to kernels that don't have the new
CFI implementation.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>