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/Eot/InfParserLite.py

@@ -52,7 +52,7 @@ class EdkInfParser(object):
         self.SourceOverridePath = SourceOverridePath
 
         # Load Inf file if filename is not None
-        if Filename != None:
+        if Filename is not None:
             self.LoadInfFile(Filename)
 
         if SourceFileList: