UPSTREAM: net: devinet: Reduce refcount before grace period

Currently, the inetdev_destroy() function waits for an RCU grace period
before decrementing the refcount and freeing memory. This causes a delay
with a new RCU configuration that tries to save power, which results in the
network interface disappearing later than expected. The resulting delay
causes test failures on ChromeOS.

Refactor the code such that the refcount is freed before the grace period
and memory is freed after. With this a ChromeOS network test passes that
does 'ip netns del' and polls for an interface disappearing, now passes.

Bug: 258241771
Bug: 222463781
Test: CQ
Reported-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Change-Id: I98b13c5a8fb9696c1111219d774cf91c8b14b4c5
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: <netdev@vger.kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
(cherry picked from commit 9d40c84c)
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/4318054


Tested-by: Joel Fernandes <joelaf@google.com>
Reviewed-by: Vineeth Pillai <vineethrp@google.com>
Commit-Queue: Joel Fernandes <joelaf@google.com>
Reviewed-by: Sean Paul <sean@poorly.run>
(cherry picked from commit 3c0f4bb182d6b0be5424947b53019e92bea8b38c)
[Cherry picked from chromeos-5.15 tree. Minor tweaks to commit message
to match Android style]
Signed-off-by: Qais Yousef <qyousef@google.com>