log: make changesetformatter pass in changectx to formatter

It wasn't necessary before, but user templates may have keywords that aren't
filled in by the changesetformatter.

mercurial/logcmdutil.py

@@ -326,6 +326,7 b' class changesetformatter(changesetprinte'
         fm = self._fm
         fm.startitem()
 
+        fm.context(ctx=ctx)
         # TODO: maybe this should be wdirrev/wdirnode?
         rev = ctx.rev()
         if rev is None:

tests/test-journal.t

@@ -279,13 +279,13 b' Test that verbose, JSON, template and co'
    children: 
   command: up 0
    rev: 0
-   children: 
+   children: 1:1e6c11564562
   command: commit -Aqm b
    rev: 1
    children: 
   command: commit -Aqm a
    rev: 0
-   children: 
+   children: 1:1e6c11564562
 
 Test for behaviour on unexpected storage version information