Address Sam's comment.

Author: eyebrowsoffire

tools/system_libs.py

@@ -1461,7 +1461,7 @@ def get_default_variation(cls, **kwargs):
 
   def get_files(self):
     files = []
-    if (self.is_ww):
+    if self.is_ww:
       files = [
         'library_wasm_worker.c',
         'wasm_worker.S',