[PATCH 1 of 2] help: fix example of revs() fileset

[Yuya Nishihara]

# HG changeset patch
# User Yuya Nishihara <yuya at tcha.org>
# Date 1489024863 -32400
#      Thu Mar 09 11:01:03 2017 +0900
# Node ID a6d5c145a6ffcaf1e9e28174a050be1457ed4362
# Parent  1871a1ee64ed49172b1568b89cdbab126284b309
help: fix example of revs() fileset

diff --git a/mercurial/help/filesets.txt b/mercurial/help/filesets.txt
--- a/mercurial/help/filesets.txt
+++ b/mercurial/help/filesets.txt
@@ -71,7 +71,7 @@ Some sample queries:
 
 - Revert files that were added to the working directory::
 
-    hg revert "set:wdir(added())"
+    hg revert "set:revs('wdir()', added())"
 
 - Remove files listed in foo.lst that contain the letter a or b::