test_cipher_gcm and using the new gcm_aes interface.
(test_main): Updated to use test_gcm_aes.
* testsuite/testutils.c (test_cipher_gcm): Deleted function.

Rev: nettle/testsuite/gcm-test.c:1.2
Rev: nettle/testsuite/testutils.c:1.13
Rev: nettle/testsuite/testutils.h:1.7