modem set-carrier: Use all remaining args for carrier name.

Use "$*" for the carrier name instead of using the needarg function,
so that we grab all remaining command-line arguments as the carrier
name. This prevents users from having to quote names like "Generic
UMTS", and allows running this from crosh, which doesn't support any
quoting.

BUG=chromium-os:19214
TEST=Run "modem set-carrier Generic UMTS" from crosh

Change-Id: Ifee1bbefd9121e1fed08c8a4745132e0ce343ba7
Reviewed-on: http://gerrit.chromium.org/gerrit/6156
Reviewed-by: Jason Glasgow <jglasgow@chromium.org>
Reviewed-by: Eric Shienbrood <ers@chromium.org>
Tested-by: Nathan J. Williams <njw@chromium.org>
diff --git a/modem b/modem
index ca284d8..2432eb1 100755
--- a/modem
+++ b/modem
@@ -167,7 +167,8 @@
 	[ -z "$mm" ] && echo "no compatible modem found" && exit 1
 	$(arg_or_default modem $(modems | head -1))
 	[ -z "$modem" ] && echo "no modem found" && exit 1
-	$(needarg carrier)
+	if [ $# -eq 0 ]; then echo 'Missing arg: carrier' && usage; fi
+	carrier="$*"
 
 	echo Setting carrier to "$carrier".  This could take up to two minutes.
 	echo Using modem "$modem"