Makefile.am: fix build of ceph_test_cors

Fix build of ceph_test_cors: use $(CRYPTO_LIBS) instead of -lcryptopp.

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>
Merge pull request #195 from dalgaaf/wip-da-fix-make

Makefile.am: fix build of ceph_test_cors

Reviewed-by: Sage Weil <sage@inktank.com>