net: warn about spaces in device names

Some commands operate on eth device names (like 'mii'), but those cannot
be passed on the command line as one argument.  So detect devices like
these and warn about them so someone will fix it.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Ben Warren <biggerbadderben@gmail.com>
diff --git a/net/eth.c b/net/eth.c
index 83d559c..de6d5c6 100644
--- a/net/eth.c
+++ b/net/eth.c
@@ -234,6 +234,9 @@
 				puts (" [PRIME]");
 			}
 
+			if (strchr(dev->name, ' '))
+				puts("\nWarning: eth device name has a space!\n");
+
 			eth_getenv_enetaddr_by_index(eth_number, env_enetaddr);
 
 			if (memcmp(env_enetaddr, "\0\0\0\0\0\0", 6)) {