Merge pull request #538 from PaulGrandperrin/master Makefile: fix linking when using BUILD_DIR

diff --git a/Makefile b/Makefile
index beccb8f..6e3dfa7 100644
--- a/Makefile
+++ b/Makefile

@@ -333,7 +333,7 @@
 	$(LD) -o $(BIN) $(OBJS) $(LCOMMON_ARCH) $(LDFLAGS)
 
 $(HFUZZ_CC_BIN): $(LCOMMON_ARCH) $(LHFUZZ_ARCH) $(LNETDRIVER_ARCH) $(HFUZZ_CC_SRCS) | $$(dir $$@)
-	$(LD) -o $@ $(SRCDIR)/$(HFUZZ_CC_SRCS) $(LCOMMON_ARCH) $(LDFLAGS) $(CFLAGS) $(CFLAGS_BLOCKS) -D_HFUZZ_INC_PATH=$(HFUZZ_INC)
+	$(LD) -o $@ $(SRCDIR)/$(HFUZZ_CC_SRCS) $(LCOMMON_ARCH) $(LDFLAGS) $(CFLAGS) $(CFLAGS_BLOCKS) -Wa,-I$(_OBJDIR) -D_HFUZZ_INC_PATH=$(HFUZZ_INC)
 
 $(LCOMMON_OBJS): $(LCOMMON_SRCS)