BaseTools/UPT: Porting UPT Tool from Python2 to Python3

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

BaseTools/Source/Python/UPT/Library/ParserValidate.py

@@ -727,7 +727,7 @@ def IsValidUserId(UserId):
 #
 def CheckUTF16FileHeader(File):
     FileIn = open(File, 'rb').read(2)
-    if FileIn != '\xff\xfe':
+    if FileIn != b'\xff\xfe':
         return False
 
     return True