cmake: fix FORCE_SSE42 (#4490)

Summary:
When HAVE_SSE42 is true, it should always add "-msse4.2 -mpclmul" no
matter if FORCE_SSE42 is true or not.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4490

Differential Revision: D10384256

Pulled By: yiwu-arbug

fbshipit-source-id: c82bc988f017981a0f84ddc136f36e2366c3ea8a

CMakeLists.txt

@@ -683,12 +683,10 @@ set(SOURCES
         utilities/write_batch_with_index/write_batch_with_index_internal.cc
         $<TARGET_OBJECTS:build_version>)
 
-if(HAVE_SSE42 AND NOT FORCE_SSE42)
+if(HAVE_SSE42 AND NOT MSVC)
-  if(NOT MSVC)
+  set_source_files_properties(
-set_source_files_properties(
+    util/crc32c.cc
-  util/crc32c.cc
+    PROPERTIES COMPILE_FLAGS "-msse4.2 -mpclmul")
-      PROPERTIES COMPILE_FLAGS "-msse4.2 -mpclmul")
-  endif()
 endif()
 
 if(HAVE_POWER8)