firewall3: fix locking issue

(cherry picked from commit c7a557861a)

package/network/config/firewall/patches/001-firewall3-fix-locking-issue.patch

@@ -0,0 +1,38 @@
+From df1306a96127e91ff2d513a0a67345baaf61d113 Mon Sep 17 00:00:00 2001
+From: Florian Eckert <fe@dev.tdt.de>
+Date: Fri, 19 Nov 2021 09:51:02 +0100
+Subject: [PATCH] firewall3: fix locking issue
+
+By calling the command 'fw3 reload' several times at the same time, I
+noticed that the locking was not working properly. It happened from time
+to time that some firewall rules were present twice in the system!
+
+By removing the 'unlink' systemcall, this error no longer occurred on my
+systems.
+
+Since fw3 does not run as a service, it makes no sense to delete this
+lock file every time a filehandler is no longer open on this lock file,
+because fw3 binary is not running.
+
+If fw3 does run as a service then we can remove this lock file on
+service stop. But this is not the case for fw3.
+
+Signed-off-by: Florian Eckert <fe@dev.tdt.de>
+---
+ utils.c | 1 -
+ 1 file changed, 1 deletion(-)
+
+diff --git a/utils.c b/utils.c
+index 17d5bf9..92e966c 100644
+--- a/utils.c
++++ b/utils.c
+@@ -397,7 +397,6 @@ fw3_unlock_path(int *fd, const char *lockpath)
+ 		warn("Cannot release exclusive lock: %s", strerror(errno));
+ 
+ 	close(*fd);
+-	unlink(FW3_LOCKFILE);
+ 
+ 	*fd = -1;
+ }
+-- 
+2.30.2