test_journal: correct potential for truncation in snprintf

fmt string is "i%d" - theoretically if the argument was eg INT_MIN this
could've been 13 chars long, which is why gcc threw a warning

1 files changed, 1 insertions, 1 deletions

diff --git a/tests/knot/test_journal.c b/tests/knot/test_journal.c
index 748ab02d0..750fad871 100644
--- a/tests/knot/test_journal.c
+++ b/tests/knot/test_journal.c
@@ -557,7 +557,7 @@ static knot_dname_t *tm_owner(const char *prefix, const knot_dname_t *apex)
 
 static knot_dname_t *tm_owner_int(int x, const knot_dname_t *apex)
 {
-	char buf[12] = { 0 };
+	char buf[13] = { 0 };
 	(void)snprintf(buf, sizeof(buf), "i%d", x);
 	return tm_owner(buf, apex);
 }