bring back mlock() of vsm mappings
bring back mlock() of vsm mappings

It got lost during the new world order megacommit
74328de8eeb2703591fe59190f73fcabf057adbe

gquintard/Varnish-Cache,gquintard/Varnish-Cache,gquintard/Varnish-Cache,gquintard/Varnish-Cache