Replace synchronize_rcu() with synchronize_net() in __netpoll_free().

synchronize_net() is RTNL-aware and will use the more efficient
synchronize_rcu_expedited() when called under RTNL lock, avoiding
the potentially expensive synchronize_rcu() in RTNL critical sections.

Since __netpoll_free() is called with RTNL held (as indicated by
ASSERT_RTNL()), this change improves performance by reducing the
time spent in the RTNL critical section.

Signed-off-by: Breno Leitao <leitao@debian.org>
---
 net/core/netpoll.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index c58faa7471650..60a05d3b7c249 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -834,7 +834,7 @@ void __netpoll_free(struct netpoll *np)
 	ASSERT_RTNL();
 
 	/* Wait for transmitting packets to finish before freeing. */
-	synchronize_rcu();
+	synchronize_net();
 	__netpoll_cleanup(np);
 	kfree(np);
 }

-- 
2.47.3