[XEND] Fix backslash escaping so it ignores escapes if they don't make sense.

Signed-off-by: Alastair Tse <atse@xensource.com>

tools/python/xen/xend/sxp.py

@@ -267,10 +267,13 @@ class Parser:
         elif c == 'x':
             self.state.fn = self.state_hex
             self.state.val = 0
-        else:
+        elif c == '0':
             self.state.fn = self.state_octal
             self.state.val = 0
             self.input_char(c)
+        else:
+            # ignore escape if it doesn't match anything we know
+            self.pop_state()
 
     def state_octal(self, c):
         def octaldigit(c):