Fix cmake

Set UR_CONFORMANCE_DEVICE_BINARIES_DIR earlier. Sometimes this var
wasn't being set before it was used.

Author: Hugh Delaney

test/conformance/CMakeLists.txt

@@ -5,6 +5,10 @@
 
 set(UR_CONFORMANCE_TEST_DIR ${CMAKE_CURRENT_SOURCE_DIR})
 
+set(UR_CONFORMANCE_DEVICE_BINARIES_DIR
+    "${CMAKE_CURRENT_BINARY_DIR}/device_binaries" CACHE INTERNAL
+    "Internal cache variable for device binaries directory")
+
 function(add_test_adapter name adapter)
     set(TEST_TARGET_NAME test-${name})
     set(TEST_NAME ${name}-${adapter})