lib.sh: remove badcmd()

it's bloat. telling the user to rtfm is something that
we already do on irc; they will still ask how to do
everything, and ignore the message from badcmd(), or
they will automatically know to rtfm.

i'm on a massive purge, removing bloat from lbmk as
part of Libreboot Build System Audit 6.

all bloat must go.

Signed-off-by: Leah Rowe <leah@libreboot.org>

script/trees

@@ -28,7 +28,7 @@ main()
 		-s) mode="savedefconfig" ;;
 		-l) mode="olddefconfig" ;;
 		-n) mode="nconfig" ;;
-		*) badcmd "invalid option '-$option'" ;;
+		*) $err "invalid option '-$option'" ;;
 		esac
 		shift; project="${OPTARG#src/}"; shift
 	done