net: Use new numeric setenv functions

Use setenv_ulong(), setenv_hex() and setenv_addr() in net/

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/net/net.c b/net/net.c
index a40cde1..df94789 100644
--- a/net/net.c
+++ b/net/net.c
@@ -528,15 +528,11 @@
 		case NETLOOP_SUCCESS:
 			net_cleanup_loop();
 			if (NetBootFileXferSize > 0) {
-				char buf[20];
 				printf("Bytes transferred = %ld (%lx hex)\n",
 					NetBootFileXferSize,
 					NetBootFileXferSize);
-				sprintf(buf, "%lX", NetBootFileXferSize);
-				setenv("filesize", buf);
-
-				sprintf(buf, "%lX", (unsigned long)load_addr);
-				setenv("fileaddr", buf);
+				setenv_hex("filesize", NetBootFileXferSize);
+				setenv_hex("fileaddr", load_addr);
 			}
 			if (protocol != NETCONS)
 				eth_halt();