mctp: perform route destruction under RCU read lock
The kernel test robot reports:
[ 843.509974][ T345] =============================
[ 843.524220][ T345] WARNING: suspicious RCU usage
[ 843.538791][ T345] 5.14.0-rc2-00606-g889b7da23abf #1 Not tainted
[ 843.553617][ T345] -----------------------------
[ 843.567412][ T345] net/mctp/route.c:310 RCU-list traversed in non-reader section!!
- we're missing the rcu read lock acquire around the destruction path.
This change adds the acquire/release - the path is already atomic, and
we're using the _rcu list iterators.
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>