af_unix: Factorise unix_find_other() based on address types.

mainline inclusion
from mainline-v5.17-rc1
commit fa39ef0e
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4OM1C
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fa39ef0e472961baef49ddb0e6f7b8ebb555bd8f



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

As done in the commit fa42d910 ("unix_bind(): take BSD and abstract
address cases into new helpers"), this patch moves BSD and abstract address
cases from unix_find_other() into unix_find_bsd() and unix_find_abstract().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Conflicts:
	net/unix/af_unix.c

Signed-off-by: Baisong Zhong <zhongbaisong@huawei.com>
Reviewed-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>