update common. to fuzz_common.h

Signed-off-by: Ben Taylor <ben.taylor@linaro.org>
diff --git a/programs/fuzz/CMakeLists.txt b/programs/fuzz/CMakeLists.txt
index 61c5b63..bd9bf91 100644
--- a/programs/fuzz/CMakeLists.txt
+++ b/programs/fuzz/CMakeLists.txt
@@ -31,7 +31,7 @@
         $<TARGET_OBJECTS:mbedtls_test_helpers>
         $<TARGET_OBJECTS:mbedtls_test>)
     if(NOT FUZZINGENGINE_LIB)
-        list(APPEND exe_sources onefile.c)
+        list(APPEND exe_sources ${MBEDTLS_DIR}/tf-psa-crypto/programs/fuzz/onefile.c)
     endif()
 
     # This emulates "if ( ... IN_LIST ... )" which becomes available in CMake 3.3