block/io: Use QEMU_LOCK_GUARD to simplify mutex handling

Replace qemu_mutex_(un)lock() calls with QEMU_LOCK_GUARD().

Signed-off-by: Evgeny Kolmakov <randomjack94dev@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Zhang Chen <zhangckid@gmail.com>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
1 file changed