[source] dnsmasq: fix instances in dhcp_add()

[LEDE Commits]

jow pushed a commit to source.git, branch master:
https://git.lede-project.org/f9f6a21c81c0a695edae24e29f938ae077d94cb3

commit f9f6a21c81c0a695edae24e29f938ae077d94cb3
Author: Eric Luehrsen <ericluehrsen at hotmail.com>
AuthorDate: Sat Feb 4 01:51:59 2017 -0500

    dnsmasq: fix instances in dhcp_add()
    
    ref commit 9525743c076393336cd2129539c974f8a01c7894
    dnsmasq: make DHCPv6 viable for standalone dnsmasq install
    Above commit broke instancing by missing filter_dnsmasq()
    as part of the dhcp_add() execution.
    
    Signed-off-by: Eric Luehrsen <ericluehrsen at hotmail.com>
---
 package/network/services/dnsmasq/files/dnsmasq.init | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/package/network/services/dnsmasq/files/dnsmasq.init b/package/network/services/dnsmasq/files/dnsmasq.init
index 954dda9..5903abe 100644
--- a/package/network/services/dnsmasq/files/dnsmasq.init
+++ b/package/network/services/dnsmasq/files/dnsmasq.init
@@ -891,13 +891,13 @@ dnsmasq_start()
 		# Enable RA feature for when/if it is constructed,
 		# and RA is selected per interface pool (RA, DHCP, or both),
 		# but no one (should) want RA broadcast in syslog
-		config_foreach dhcp_add dhcp
+		config_foreach filter_dnsmasq dhcp dhcp_add "$cfg"
 		xappend "--enable-ra"
 		xappend "--quiet-ra"
 		append_bool "$cfg" quietdhcp "--quiet-dhcp6"
 
 	elif [ "$DNSMASQ_DHCP_VER" -gt 0 ] ; then
-		config_foreach dhcp_add dhcp
+		config_foreach filter_dnsmasq dhcp dhcp_add "$cfg"
 	fi