fib: skip byte swap on n_paths in mroute details

fib: skip byte swap on n_paths in mroute details

Type: fix

While preparing to send a ip_mroute_details API message, the number
of paths for a multicast route is stored in an int in
send_ip_mroute_details(). Before the value in the int is copied into
the field n_paths in the API message, the byte order is swapped.
This results in n_paths getting set to 0.

Change the int to a u8 and omit the byte swap so API clients can
receive data on multicast route paths.

Change-Id: Ie6dcb0f7b135c5b5deeeb2e44147560dbbb12507
Signed-off-by: Matthew Smith <mgsmith@netgate.com>