[ Upstream commit 64b9d16e2d02ca6e5dc8fcd30cfd52b0ecaaa8f4 ]

Clang warns:

drivers/atm/zatm.c:513:7: error: while loop has empty body
[-Werror,-Wempty-body]
        zwait;
             ^
drivers/atm/zatm.c:513:7: note: put the semicolon on a separate line to
silence this warning

Get rid of this warning by using an empty do-while loop. While we're at
it, add parentheses to make it clear that this is a function-like macro.

Link: https://github.com/ClangBuiltLinux/linux/issues/42Suggested-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>