Revert "Flip equality to use mock calls' __eq__"

This reverts commit 94ddf54.

Lib/unittest/mock.py

@@ -337,7 +337,7 @@ def __contains__(self, value):
 
  for i in range(0, len_self - len_value + 1):
  sub_list = self[i:i+len_value]
- if value == sub_list:
+ if sub_list == value:
  return True
  return False