Remove Depfiles from bootstrap.Args .

It is not used anymore; Soong assumes that the depfile is just the name
of the output file with a ".d" suffix.

Test: Presubmits.
Change-Id: Ifbf722dcdffc8420e12a032e23ab791a6be5a736

bootstrap/bootstrap.go

@@ -133,7 +133,6 @@ var (
 				`    --top "$$TOP" ` +
 				`    --out "$soongOutDir" ` +
 				`    -n "$outDir" ` +
-				`    -d "$out.d" ` +
 				`    $extra`,
 			CommandDeps: []string{"$builder"},
 			Description: "$builder $out",

bootstrap/command.go

@@ -32,7 +32,6 @@ import (
 type Args struct {
 	OutFile                  string
 	Subninjas                []string
-	DepFile                  string
 	Cpuprofile               string
 	Memprofile               string
 	DelveListen              string