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_ubi.c b/common/cmd_ubi.c
index 305e2e1..b99fd58 100644
--- a/common/cmd_ubi.c
+++ b/common/cmd_ubi.c
@@ -600,7 +600,7 @@
 }
 
 U_BOOT_CMD(ubi, 6, 1, do_ubi,
-	"ubi      - ubi commands\n",
+	"ubi commands",
 	"part [nand|nor|onenand] [part]"
 		" - Show or set current partition\n"
 	"ubi info [l[ayout]]"