net: fib_rules: Correctly set table field when table number exceeds 8 bits

[ Upstream commit 540e585a79e9d643ede077b73bcc7aa2d7b4d919 ]

In 709772e6, RT_TABLE_COMPAT was added to
allow legacy software to deal with routing table numbers >= 256, but the
same change to FIB rule queries was overlooked.

Signed-off-by: Jethro Beekman <jethro@fortanix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>