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/Eot/EotGlobalData.py

@@ -11,7 +11,7 @@ from Common.LongFilePathSupport import OpenLongFilePath as open
 gEFI_SOURCE = ''
 gEDK_SOURCE = ''
 gWORKSPACE = ''
-gSHELL_INF = 'Application\Shell'
+gSHELL_INF = 'Application\\Shell'
 gMAKE_FILE = ''
 gDSC_FILE = ''
 gFV_FILE = []