This patch prevents the possible not NULL terminating problem.
ifr_name's array size is IFNAMSIZ. So If bridge has IFNAMSIZ size,
the name string will be not NULL terminating.
Support for extension headers is mandatory functionality. This patch
add support to it and leave responsibility for processing extension
header and sending setup success response to kernel.
This patch is necessary to pass PTS bnep test TC_CTRL_BV_19_C.
