net: igmp: increase size of mr_ifc_count

stable inclusion
from stable-5.10.60
commit 4344440d91b347bd2b1c7367a7a523e1d2afd8ba
bugzilla: 177018 https://gitee.com/openeuler/kernel/issues/I4EAUG

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4344440d91b347bd2b1c7367a7a523e1d2afd8ba



--------------------------------

[ Upstream commit b69dd5b3 ]

Some arches support cmpxchg() on 4-byte and 8-byte only.
Increase mr_ifc_count width to 32bit to fix this problem.

Fixes: 4a2b285e ("net: igmp: fix data-race in igmp_ifc_timer_expire()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20210811195715.3684218-1-eric.dumazet@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>