Eliminate ocb.cc test program (closes mobile-shell#408)

This test doesn't return an error on failure and also was triggering a
stack protector warning on some platforms. We have an end-to-end test of
OCB in src/tests/ocb-aes.cc that seems to work well.

src/crypto/Makefile.am

@@ -15,10 +15,3 @@ libmoshcrypto_a_SOURCES = \
 	crypto.cc \
 	crypto.h \
 	prng.h
-
-check_PROGRAMS = ocb-test
-TESTS = ocb-test
-
-ocb_test_SOURCES = $(OCB_SRCS)
-ocb_test_CPPFLAGS = -DOCB_TEST_PROGRAM
-ocb_test_LDADD = $(OPENSSL_LIBS)