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_autoscript.c b/common/cmd_autoscript.c
index 4517ac8..e5a9bc0 100644
--- a/common/cmd_autoscript.c
+++ b/common/cmd_autoscript.c
@@ -230,7 +230,7 @@
 
 U_BOOT_CMD(
 	autoscr, 2, 0,	do_autoscript,
-	"autoscr - run script from memory\n",
+	"run script from memory",
 	"[addr] - run script starting at addr"
 	" - A valid autoscr header must be present\n"
 #if defined(CONFIG_FIT)