bridge: netfilter: using strlcpy() instead of strncpy()

'name' has already set all zero when it is defined, so not need let
strncpy() to pad it again.

'name' is a string, better always let is NUL terminated, so use
strlcpy() instead of strncpy().

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Acked-by: Bart De Schuymer <bdschuym@pandora.be>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>