[LEDE-DEV] [PATCH odhcpd v2] dhcpv6-ia: Check lockf return value

[Florian Fainelli]

Check the lockf return value to fix the following warning/error:

/home/fainelli/dev/openwrt/trunk/build_dir/target-mipsel-linux-gnu_glibc/odhcpd-2017-02-21-1b630f8b/src/dhcpv6-ia.c: In function 'dhcpv6_write_statefile':
/home/fainelli/dev/openwrt/trunk/build_dir/target-mipsel-linux-gnu_glibc/odhcpd-2017-02-21-1b630f8b/src/dhcpv6-ia.c:246:8: error: ignoring return value of 'lockf', declared with attribute warn_unused_result [-Werror=unused-result]
   lockf(fd, F_LOCK, 0);
        ^
cc1: all warnings being treated as errors

Signed-off-by: Florian Fainelli <f.fainelli at gmail.com>
---
Changes in v2:
- provide the warning being fixed here

 src/dhcpv6-ia.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/dhcpv6-ia.c b/src/dhcpv6-ia.c
index 888634fe1f29..fb5044884441 100644
--- a/src/dhcpv6-ia.c
+++ b/src/dhcpv6-ia.c
@@ -242,8 +242,12 @@ void dhcpv6_write_statefile(void)
 		int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
 		if (fd < 0)
 			return;
-
-		lockf(fd, F_LOCK, 0);
+		int ret;
+		ret = lockf(fd, F_LOCK, 0);
+		if (ret < 0) {
+			close(fd);
+			return;
+		}
 		if (ftruncate(fd, 0) < 0) {}
 
 		FILE *fp = fdopen(fd, "w");
-- 
2.9.3