Command usage cleanup

Remove command name from all command "usage" fields and update
common/command.c to display "name - usage" instead of
just "usage". Also remove newlines from command usage fields.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/common/cmd_usb.c b/common/cmd_usb.c
index 46d6eea..423a29f 100644
--- a/common/cmd_usb.c
+++ b/common/cmd_usb.c
@@ -666,7 +666,7 @@
 #ifdef CONFIG_USB_STORAGE
 U_BOOT_CMD(
 	usb,	5,	1,	do_usb,
-	"usb     - USB sub-system\n",
+	"USB sub-system",
 	"reset - reset (rescan) USB controller\n"
 	"usb stop [f]  - stop USB [f]=force stop\n"
 	"usb tree  - show USB device tree\n"
@@ -682,14 +682,14 @@
 
 U_BOOT_CMD(
 	usbboot,	3,	1,	do_usbboot,
-	"usbboot - boot from USB device\n",
+	"boot from USB device",
 	"loadAddr dev:part\n"
 );
 
 #else
 U_BOOT_CMD(
 	usb,	5,	1,	do_usb,
-	"usb     - USB sub-system\n",
+	"USB sub-system",
 	"reset - reset (rescan) USB controller\n"
 	"usb  tree  - show USB device tree\n"
 	"usb  info [dev] - show available USB devices\n"