log: syslog: Handle errors in net_init

Since the previous patch, net_init now exposes some errors, so check for
them.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/common/log_syslog.c b/common/log_syslog.c
index 2ae703f..4eb0915 100644
--- a/common/log_syslog.c
+++ b/common/log_syslog.c
@@ -39,7 +39,9 @@
 	char *log_hostname;
 
 	/* Setup packet buffers */
-	net_init();
+	ret = net_init();
+	if (ret)
+		return ret;
 	/* Disable hardware and put it into the reset state */
 	eth_halt();
 	/* Set current device according to environment variables */