BaseTools: Remove equality operator with None

replace "== None" with "is None" and "!= None" with "is not None"

Cc: Yonghong Zhu <yonghong.zhu@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jaben Carsey <jaben.carsey@intel.com>
Reviewed-by: Yonghong Zhu <yonghong.zhu@intel.com>

BaseTools/Source/Python/Common/Dictionary.py

@@ -54,7 +54,7 @@ def ConvertTextFileToDictionary(FileName, Dictionary, CommentCharacter, KeySplit
 # @param Dict:  The dictionary to be printed
 #
 def printDict(Dict):
-    if Dict != None:
+    if Dict is not None:
         KeyList = Dict.keys()
         for Key in KeyList:
             if Dict[Key] != '':