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/board/MAI/AmigaOneG3SE/cmd_boota.c b/board/MAI/AmigaOneG3SE/cmd_boota.c
index 949af18..6b955d8 100644
--- a/board/MAI/AmigaOneG3SE/cmd_boota.c
+++ b/board/MAI/AmigaOneG3SE/cmd_boota.c
@@ -122,7 +122,7 @@
 #if defined(CONFIG_AMIGAONEG3SE) && defined(CONFIG_CMD_BSP)
 U_BOOT_CMD(
 	boota,   3,      1,      do_boota,
-	"boota   - boot an Amiga kernel\n",
+	"boot an Amiga kernel",
 	"address disk"
 );
 #endif /* _CMD_BOOTA_H */