tests: clean up test-rollback.t

The last comment is on the last file line and is useless, seems
like it was introduced in 8fdc11fec6ae during unification.

tests/test-rollback.t

@@ -1,92 +1,91
 
   $ mkdir t
   $ cd t
   $ hg init
   $ echo a > a
   $ hg add a
   $ hg commit -m "test"
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   1 files, 1 changesets, 1 total revisions
   $ hg parents
   changeset:   0:acb14030fe0a
   tag:         tip
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     test
   
   $ hg status
   $ hg rollback
   rolling back to revision -1 (undo commit)
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   0 files, 0 changesets, 0 total revisions
   $ hg parents
   $ hg status
   A a
 
 Test issue 902
 
   $ hg commit -m "test2"
   $ hg branch test
   marked working directory as branch test
   $ hg rollback
   rolling back to revision -1 (undo commit)
   $ hg branch
   default
 
 Test issue 1635 (commit message saved)
 .hg/last-message.txt:
 
   $ cat .hg/last-message.txt ; echo
   test2
 
 Test rollback of hg before issue 902 was fixed
 
   $ hg commit -m "test3"
   $ hg branch test
   marked working directory as branch test
   $ rm .hg/undo.branch
   $ hg rollback
   rolling back to revision -1 (undo commit)
   Named branch could not be reset, current branch still is: test
   $ hg branch
   test
 
 rollback by pretxncommit saves commit message (issue 1635)
 
   $ echo a >> a
   $ hg --config hooks.pretxncommit=false commit -m"precious commit message"
   transaction abort!
   rollback completed
   abort: pretxncommit hook exited with status * (glob)
   [255]
 
 .hg/last-message.txt:
 
   $ cat .hg/last-message.txt ; echo
   precious commit message
-  $ echo '% same thing, but run $EDITOR'
-  % same thing, but run $EDITOR
+
+same thing, but run $EDITOR
+
   $ cat > editor << '__EOF__'
   > #!/bin/sh
   > echo "another precious commit message" > "$1"
   > __EOF__
   $ chmod +x editor
   $ HGEDITOR="'`pwd`'"/editor hg --config hooks.pretxncommit=false commit 2>&1
   transaction abort!
   rollback completed
   note: commit message saved in .hg/last-message.txt
   abort: pretxncommit hook exited with status * (glob)
   [255]
   $ cat .hg/last-message.txt
   another precious commit message
 
-.hg/last-message.txt:
-