BaseTools: Refactor python except statements

Convert "except ... ," to "except ... as" to be compatible with python3.
Based on "futurize -f lib2to3.fixes.fix_except"

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

BaseTools/Source/Python/Ecc/c.py

@@ -2633,7 +2633,7 @@ if __name__ == '__main__':
 #    CollectSourceCodeDataIntoDB(sys.argv[1])
     try:
         test_file = sys.argv[1]
-    except IndexError, v:
+    except IndexError as v:
         print "Usage: %s filename" % sys.argv[0]
         sys.exit(1)
     MsgList = CheckFuncHeaderDoxygenComments(test_file)