soong: generator: Replace android.SourceDepTag usage with IsSourceDepTagWithOutputTag

Change-Id: Iad5d9a07d06a7efda233cc8d3387e8db5c3b0ab5
diff --git a/build/soong/generator/generator.go b/build/soong/generator/generator.go
index 74910a3..0c92b79 100644
--- a/build/soong/generator/generator.go
+++ b/build/soong/generator/generator.go
@@ -149,8 +149,6 @@
 	if len(g.properties.Tools) > 0 {
 		ctx.VisitDirectDepsBlueprint(func(module blueprint.Module) {
 			switch ctx.OtherModuleDependencyTag(module) {
-			case android.SourceDepTag:
-				// Nothing to do
 			case hostToolDepTag:
 				tool := ctx.OtherModuleName(module)
 				var path android.OptionalPath
@@ -188,7 +186,9 @@
 					ctx.ModuleErrorf("host tool %q missing output file", tool)
 				}
 			default:
-				ctx.ModuleErrorf("unknown dependency on %q", ctx.OtherModuleName(module))
+				if !android.IsSourceDepTagWithOutputTag(ctx.OtherModuleDependencyTag(module), "") {
+					ctx.ModuleErrorf("unknown dependency on %q", ctx.OtherModuleName(module))
+				}
 			}
 		})
 	}