Coverity now noticed we're checking most lseek() return values, but
not this. Not really relevant, but it doesn't hurt to check we can
actually seek before reading lines.

Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com>
Reviewed-by: David Gibson <david(a)gibson.dropbear.id.au>
---
 util.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/util.c b/util.c
index b366167..5b1e08a 100644
--- a/util.c
+++ b/util.c
@@ -311,10 +311,14 @@ void procfs_scan_listen(struct ctx *c, uint8_t proto, int ip_version, int ns,
 			path = "/proc/net/udp6";
 	}
 
-	if (*fd != -1)
-		lseek(*fd, 0, SEEK_SET);
-	else if ((*fd = open(path, O_RDONLY | O_CLOEXEC)) < 0)
+	if (*fd != -1) {
+		if (lseek(*fd, 0, SEEK_SET)) {
+			warn("lseek() failed on %s: %s", path, strerror(errno));
+			return;
+		}
+	} else if ((*fd = open(path, O_RDONLY | O_CLOEXEC)) < 0) {
 		return;
+	}
 
 	lineread_init(&lr, *fd);
 	lineread_get(&lr, &line); /* throw away header */
-- 
2.35.1