[PATCH] um: Use swap() instead of open coding it

[Jiapeng Chong]

Swap is a function interface that provides exchange function. To avoid
code duplication, we can use swap function.

./arch/um/os-Linux/sigio.c:81:28-29: WARNING opportunity for swap().

Reported-by: Abaci Robot <abaci@xxxxxxxxxxxxxxxxx>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=7607
Signed-off-by: Jiapeng Chong <jiapeng.chong@xxxxxxxxxxxxxxxxx>
---
 arch/um/os-Linux/sigio.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/um/os-Linux/sigio.c b/arch/um/os-Linux/sigio.c
index 9e71794839e8..1eb15f3cfdc8 100644
--- a/arch/um/os-Linux/sigio.c
+++ b/arch/um/os-Linux/sigio.c
@@ -50,7 +50,7 @@ static struct pollfds all_sigio_fds;
 
 static int write_sigio_thread(void *unused)
 {
-	struct pollfds *fds, tmp;
+	struct pollfds *fds;
 	struct pollfd *p;
 	int i, n, respond_fd;
 	char c;
@@ -77,9 +77,7 @@ static int write_sigio_thread(void *unused)
 					       "write_sigio_thread : "
 					       "read on socket failed, "
 					       "err = %d\n", errno);
-				tmp = current_poll;
-				current_poll = next_poll;
-				next_poll = tmp;
+				swap(current_poll, next_poll);
 				respond_fd = sigio_private[1];
 			}
 			else {
-- 
2.20.1.7.g153144c