improve example even more

src/lib/libc/stdlib/malloc.3

@@ -30,7 +30,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"	$OpenBSD: malloc.3,v 1.29 2003/09/18 22:49:13 tedu Exp $
+.\"	$OpenBSD: malloc.3,v 1.30 2003/09/25 11:10:56 deraadt Exp $
 .\"
 .Dd August 27, 1996
 .Dt MALLOC 3
@@ -158,13 +158,14 @@ indicates that the old object still remains allocated.
 Better code looks like this:
 .Bd -literal -offset indent
 newsize = size + 50;
-if ((p2 = realloc(p, newsize)) == NULL) {
+if ((newp = realloc(p, newsize)) == NULL) {
 	if (p)
 		free(p);
 	p = NULL;
+	size = 0;
 	return (NULL);
 }
-p = p2;
+p = newp;
 size = newsize;
 .Ed
 .Pp