[IPV4] fib: convert reader/writer to spinlock

Ther is no point in using a more expensive reader/writer lock
for a low contention lock like the fib_info_lock. The only
reader case is in handling route redirects.

Signed-off-by: Stephen Hemminger <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
1 file changed