cmake: do not set libsuffix=64 on MacOS. fix issue #963
diff --git a/CMakeLists.txt b/CMakeLists.txt
index d723ae3..dad1833 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -466,7 +466,7 @@
 ### test library 64bit routine:
 get_property(LIB64 GLOBAL PROPERTY FIND_LIBRARY_USE_LIB64_PATHS)
 
-if ("${LIB64}" STREQUAL "TRUE")
+if (NOT APPLE AND "${LIB64}" STREQUAL "TRUE")
     set(LIBSUFFIX 64)
 else()
     set(LIBSUFFIX "")