state: fix usage of an unassigned variable

The variable iv was used in earlier iterations of the patches and was dropped
since we made sure 'version' is always int. This usage of 'iv' should have been
replaced by 'version' in the original patch only.

Differential Revision: https://phab.mercurial-scm.org/D3640

mercurial/state.py

@@ -62,7 +62,7 b' class cmdstate(object):'
                                          " an integer")
 
         with self._repo.vfs(self.fname, 'wb', atomictemp=True) as fp:
-            fp.write('%d\n' % iv)
+            fp.write('%d\n' % version)
             cbor.dump(self.opts, fp, canonical=True)
 
     def _read(self):