crypto: gcm - Fix error return code in crypto_gcm_create_common()

Fix to return error code -EINVAL from the invalid alg ivsize error
handling case instead of 0, as done elsewhere in this function.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>