Improve portability of init script by declaring resolvfile as local
in dnsmasq_stop function.
Fixes resolvfile being set for older busybox versions in dnsmasq_start
in a multi dnsmasq instance config when doing restart; this happens when
the last instance has a resolvfile configured while the first instance
being started has noresolv set to 1.
Base on a patch by "Phil"
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>