Options processing: remove redundant check

Bug: 172923994
Test: N/A
Change-Id: I2b07c775f8e3cad78eb6992d3522bef3a9b701b8
diff --git a/mk2rbc/cmd/mk2rbc.go b/mk2rbc/cmd/mk2rbc.go
index aa01e3b..4d3d8d8 100644
--- a/mk2rbc/cmd/mk2rbc.go
+++ b/mk2rbc/cmd/mk2rbc.go
@@ -138,9 +138,7 @@
 		}
 		os.Exit(0)
 	}
-	if len(flag.Args()) == 0 {
-		flag.Usage()
-	}
+
 	// Convert!
 	ok := true
 	if *launcher != "" {