tests: don't hardcode errno==2 for ENOENT

Hurd seems to set ENOENT to 2 + 2**30, unlike everyone else.

tests/test-acl.t

@@ -889,7 +889,7 file specified by acl.config does not ex
   added 3 changesets with 3 changes to 3 files
   calling hook pretxnchangegroup.acl: hgext.acl.hook
   acl: checking access for user "barney"
-  error: pretxnchangegroup.acl hook raised an exception: [Errno 2] *: '../acl.config' (glob)
+  error: pretxnchangegroup.acl hook raised an exception: [Errno *] *: '../acl.config' (glob)
   transaction abort!
   rollback completed
   abort: *: ../acl.config (glob)

tests/test-qrecord.t

@@ -110,7 +110,7 help (bad mq)
 
   $ echo "mq=nonexistent" >> $HGRCPATH
   $ hg help qrecord
-  *** failed to import extension mq from nonexistent: [Errno 2] * (glob)
+  *** failed to import extension mq from nonexistent: [Errno *] * (glob)
   hg qrecord [OPTION]... PATCH [FILE]...
   
   interactively record a new patch