BaseTools: Fix Python SyntaxWarning

- Windows paths must be escaped
- Regex should use raw strings

Signed-off-by: Tim Crawford <tcrawford@system76.com>

BaseTools/Source/Python/UPT/Parser/DecParserMisc.py

@@ -25,10 +25,10 @@ from Library.ExpressionValidate import IsValidStringTest
 from Library.Misc import CheckGuidRegFormat
 
 TOOL_NAME = 'DecParser'
-VERSION_PATTERN = '[0-9]+(\.[0-9]+)?'
-CVAR_PATTERN = '[_a-zA-Z][a-zA-Z0-9_]*'
-PCD_TOKEN_PATTERN = '(0[xX]0*[a-fA-F0-9]{1,8})|([0-9]+)'
-MACRO_PATTERN = '[A-Z][_A-Z0-9]*'
+VERSION_PATTERN = r'[0-9]+(\.[0-9]+)?'
+CVAR_PATTERN = r'[_a-zA-Z][a-zA-Z0-9_]*'
+PCD_TOKEN_PATTERN = r'(0[xX]0*[a-fA-F0-9]{1,8})|([0-9]+)'
+MACRO_PATTERN = r'[A-Z][_A-Z0-9]*'
 
 ## FileContent
 # Class to hold DEC file information