[BRIDGE]: Section fix.

WARNING: vmlinux.o(.init.text+0x204e2): Section mismatch: reference to .exit.text:br_fdb_fini (between 'br_init' and 'br_fdb_init')

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>