mc_cmds: fix test on sparc & when iface joined multiple groups

/proc/net/igmp can have this:

* When iface joinded multiple groups:
5       ltp_ns_veth2:     2      V3
                                FB0000E0     1 0:00000000  0
                                010000E0     1 0:00000000  0

* For sparc byte order is different:
3       ltp_ns_veth2:     1      V3
                                E0000001     1 0:00000000  0

Fix both by grepping 'ip maddr' output from target interface name
till the next interface entry.

Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
1 file changed