dlm: replace usage of found with dedicated list iterator variable

stable inclusion
from stable-v5.10.193
commit e850cd32df9f8022e9f1ef0818ec8651e58c80d2
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I9399M

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e850cd32df9f8022e9f1ef0818ec8651e58c80d2

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

[ Upstream commit dc1acd5c ]

To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.

To *never* use the list iterator variable after the loop it was
concluded to use a separate iterator variable instead of a
found boolean [1].

This removes the need to use a found variable and simply checking if
the variable was set, can determine if the break/goto was hit.

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/

 [1]
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Stable-dep-of: 57e2c2f2 ("fs: dlm: fix mismatch of plock results from userspace")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>