libventi: return value nits

src/libventi/packet.c

diff --git a/src/libventi/packet.c b/src/libventi/packet.c
index 2c3dcd7..d19d853 100644
--- a/src/libventi/packet.c
+++ b/src/libventi/packet.c
@@ -888,7 +888,7 @@
 
 	if(n < 0 || n > MaxFragSize) {
 		werrstr(EPacketSize);
-		return 0;
+		return nil;
 	}
 	if(n <= SmallMemSize) {
 		lock(&freelist.lk);

src/libventi/send.c

diff --git a/src/libventi/send.c b/src/libventi/send.c
index 70cc827..2b88818 100644
--- a/src/libventi/send.c
+++ b/src/libventi/send.c
@@ -39,7 +39,7 @@
 		if(write(z->outfd, ioc.addr, ioc.len) < ioc.len){
 			vtlog(VtServerLog, "<font size=-1>%T %s:</font> sending packet %p: %r<br>\n", z->addr, p);
 			packetfree(p);
-			return 0;
+			return -1;
 		}
 		packetconsume(p, nil, ioc.len);
 		tot += ioc.len;