clases/lib: Use modern exception syntax

Update older code to use modern exception handling syntax which
is the form accepted by python 3.

(From OE-Core rev: b010501cd089e649a68f683be0cf4d0aac90fbe3)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oe/patch.py

@@ -392,7 +392,7 @@ class UserResolver(Resolver):
         os.chdir(self.patchset.dir)
         try:
             self.patchset.Push(False)
-        except CmdError, v:
+        except CmdError as v:
             # Patch application failed
             patchcmd = self.patchset.Push(True, False, False)