fix OSS test cert discovery

Summary: Enable finding folly test certs in cmake build via folly_test_util FOLLY_CERTS_DIR rather than hardcoding the path so that the certs can be found. The define already existed but was not set/used in the cmake build

Reviewed By: bigfootjon

Differential Revision: D66074308

fbshipit-source-id: 22417237f1341918b3e02f52fe093ab1d38683d9

CMakeLists.txt

@@ -481,6 +481,9 @@ add_library(folly_test_util
   ${FOLLY_DIR}/test/DeterministicSchedule.cpp
   ${FOLLY_DIR}/json/JsonTestUtil.cpp
 )
+target_compile_definitions(folly_test_util PUBLIC
+  FOLLY_CERTS_DIR="${FOLLY_DIR}/io/async/test/certs"
+)
 set_property(TARGET folly_test_util PROPERTY VERSION ${PACKAGE_VERSION})
 target_link_libraries(folly_test_util
   PUBLIC