[PATCH 5 of 5] destutil: remove dead code about non-linear updates

[Martin von Zweigbergk]

# HG changeset patch
# User Martin von Zweigbergk <martinvonz at google.com>
# Date 1486501890 28800
#      Tue Feb 07 13:11:30 2017 -0800
# Node ID a85eff052c57bde4c6100a23888c471f595c2d85
# Parent  05ff0729e9f4166f1f08855d25aa6ed4dddf155b
destutil: remove dead code about non-linear updates

IIUC, the non-linear updates no longer happen by default since
6b1fc09c699a (update: change default destination to tipmost descendant
(issue4673) (BC), 2016-02-02), and it was only if they happened by
default that we used to error out, so there is no longer a need to
handle this case.

diff -r 05ff0729e9f4 -r a85eff052c57 mercurial/destutil.py
--- a/mercurial/destutil.py	Thu Feb 09 09:55:31 2017 -0800
+++ b/mercurial/destutil.py	Tue Feb 07 13:11:30 2017 -0800
@@ -37,10 +37,6 @@
                     hint = _("commit and merge, or update --clean to"
                              " discard changes")
                     raise error.UpdateAbort(msg, hint=hint)
-                elif not check:  # destination is not a descendant.
-                    msg = _("not a linear update")
-                    hint = _("merge or update --check to force update")
-                    raise error.UpdateAbort(msg, hint=hint)
 
 def _destupdateobs(repo, clean, check):
     """decide of an update destination from obsolescence markers"""