lz4 doesn't support "make distclean", so don't use it.

Change-Id: Ie63c58752d93be9e4027a55074b6a8fbf81986b3
Reviewed-on: https://code.wireshark.org/review/22411
Reviewed-by: Guy Harris <guy@alum.mit.edu>

macosx-setup.sh

@@ -1600,7 +1600,10 @@ uninstall_lz4() {
         echo "Uninstalling lz4:"
         cd lz4-$installed_lz4_version
         $DO_MAKE_UNINSTALL || exit 1
-        make distclean || exit 1
+        #
+        # lz4 uses cmake and doesn't support "make distclean"
+        #
+        # make distclean || exit 1
         cd ..
         rm lz4-$installed_lz4_version-done