Close opened paths

Test: m nothing
Change-Id: I7fcc8e2fdbca1cd231ff1e72b02156f12078072b
diff --git a/android/soong_config_modules.go b/android/soong_config_modules.go
index 91bbce6..bd73645 100644
--- a/android/soong_config_modules.go
+++ b/android/soong_config_modules.go
@@ -378,6 +378,7 @@
 			ctx.PropertyErrorf("from", "failed to open %q: %s", from, err)
 			return (map[string]blueprint.ModuleFactory)(nil)
 		}
+		defer r.Close()
 
 		mtDef, errs := soongconfig.Parse(r, from)
 		if ctx.Config().runningAsBp2Build {