[PATCH 4 of 6 mergedriver] strip: switch to mergestate.fresh()

[Siddharth Agarwal]

# HG changeset patch
# User Siddharth Agarwal <sid0 at fb.com>
# Date 1447797146 28800
#      Tue Nov 17 13:52:26 2015 -0800
# Node ID 071c1dffd74e5412b9e6bca877b0029d6dc9c54a
# Parent  bb1b25b554d6efe340f3c74b58fec40cd56fd557
strip: switch to mergestate.fresh()

See the previous patches for why we're doing this.

diff --git a/hgext/strip.py b/hgext/strip.py
--- a/hgext/strip.py
+++ b/hgext/strip.py
@@ -208,8 +208,7 @@ def stripcmd(ui, repo, *revs, **opts):
             repo.dirstate.write(repo.currenttransaction())
 
             # clear resolve state
-            ms = merge.mergestate(repo)
-            ms.reset(repo['.'].node())
+            merge.mergestate.fresh(repo, repo['.'].node())
 
             update = False