Fix the following coccicheck REVIEW:
Use swap() instead of reimplementing it.
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: chiminghao <chi.minghao@zte.com.cn>
[bentiss: rewrote commit title]
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20211109082610.131341-1-chi.minghao@zte.com.cn