cmdutil: say that `graft --stop` stops the graft instead of aborting

I am going to add a --abort flag to graft soon, so we make sure we differentiate
between the what --stop flag does and what --abort does and don't use the words
interchangeably.

Differential Revision: https://phab.mercurial-scm.org/D3735

mercurial/cmdutil.py

@@ -3173,7 +3173,7 b' summaryremotehooks = util.hooks()'
 # (state file, clearable, allowcommit, error, hint)
 unfinishedstates = [
     ('graftstate', True, False, _('graft in progress'),
-     _("use 'hg graft --continue' or 'hg graft --stop' to abort")),
+     _("use 'hg graft --continue' or 'hg graft --stop' to stop")),
     ('updatestate', True, False, _('last update was interrupted'),
      _("use 'hg update' to get a consistent checkout"))
     ]

tests/test-graft.t

@@ -244,7 +244,7 b' Commit while interrupted should fail:'
 
   $ hg ci -m 'commit interrupted graft'
   abort: graft in progress
-  (use 'hg graft --continue' or 'hg graft --stop' to abort)
+  (use 'hg graft --continue' or 'hg graft --stop' to stop)
   [255]
 
 Abort the graft and try committing: