fib: changing parsing order to avoid corner case

fib: changing parsing order to avoid corner case

mfib interface flags are parsed before the interface name. For some
specific names, this creates a bug when adding routes.

ex: ip route add 10.0.2.0/24 via FortyGigabitEthernetd8/0/0
The 'F' at the beginnig of the interface name is parsed as the
"Forward" flag. Because of that, the interface name parsed is
"ortyGigabitEthernetd8/0/0" which results in a parsing error.

Type: fix

Signed-off-by: Arthur de Kerhor <arthurdekerhor@gmail.com>
Change-Id: Ib76c2f86416455841f910f7b466b467001072b70