Merge pull request #3753 from facebook/make2

minor Makefile refactoring

diff --cc tests/Makefile
index 700c64b1d17b1f5c31b7a7217d60619334e1ecda,740bb59593b77916e54874b2eefc503ae3cff1de..4eb77fdec6b3ddbf57f6a9889a56cc27565918bf
--- 1/tests/Makefile
--- 2/tests/Makefile
+++ b/tests/Makefile
@@@ -249,11 -247,10 +247,11 @@@ checkTag.o : $(LIB_SRCDIR)/zstd.
  
  .PHONY: clean
  clean:
-       $(MAKE) -C $(ZSTDDIR) clean
+       $(MAKE) -C $(LIB_SRCDIR) clean
        $(MAKE) -C $(PRGDIR) clean
 -      $(RM) -fR $(TESTARTEFACT)
 -      $(RM) -rf tmp*  # some test directories are named tmp*
 +      $(MAKE) -C fuzz clean
 +      $(RM) -R $(TESTARTEFACT)
 +      $(RM) -r tmp*  # some test directories are named tmp*
        $(RM) $(CLEAN) core *.o *.tmp result* *.gcda dictionary *.zst \
          $(PRGDIR)/zstd$(EXT) $(PRGDIR)/zstd32$(EXT) \
          fullbench-dll$(EXT) fuzzer-dll$(EXT) zstreamtest-dll$(EXT)

diff --cc tests/fuzz/Makefile
Simple merge