ipv6 route: Convert rt6_device_match() to use RT6_LOOKUP_F_xxx flags.

The commit 77d16f45 ("[IPV6] ROUTE:
Unify RT6_F_xxx and RT6_SELECT_F_xxx flags") intended to pass various
routing lookup hints around RT6_LOOKUP_F_xxx flags, but conversion was
missing for rt6_device_match().

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>