wrapfunction: use sysstr instead of bytes as argument in "perf"

This is as valid and simpler, it will help us to eventually get ride of
`safehasattr`.

contrib/perf.py

@@ -4421,7 +4421,8 b' def uisetup(ui):'
                 )
             return orig(repo, cmd, file_, opts)
 
-        extensions.wrapfunction(cmdutil, b'openrevlog', openrevlog)
+        name = _sysstr(b'openrevlog')
+        extensions.wrapfunction(cmdutil, name, openrevlog)
 
 
 @command(