tests/sysinfo.c: use libtests

* tests/sysinfo.c (main): Use perror_msg_and_skip.
diff --git a/tests/sysinfo.c b/tests/sysinfo.c
index 0188002..cbf975d 100644
--- a/tests/sysinfo.c
+++ b/tests/sysinfo.c
@@ -25,6 +25,7 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include "tests.h"
 #include <stdio.h>
 #include <sys/sysinfo.h>
 
@@ -32,8 +33,8 @@
 main (void)
 {
 	struct sysinfo si;
-	if (sysinfo(&si) == -1)
-		return 77;
+	if (sysinfo(&si))
+		perror_msg_and_skip("sysinfo");
 	printf("sysinfo({uptime=%llu"
 		", loads=[%llu, %llu, %llu]"
 		", totalram=%llu"