engine: resources: Remove named return params

Named return params aren't a favourite feature of mine, and they're
rarely used in the resource writing. They keep popping up because I once
used them and we've been copying and pasting code ever since. Get rid of
them all to help prevent the unnecessary spread.

engine/resources/pkg.go

@@ -262,7 +262,7 @@ func (obj *PkgRes) populateFileList() error {
 
 // CheckApply checks the resource state and applies the resource if the bool
 // input is true. It returns error info and if the state check passed or not.
-func (obj *PkgRes) CheckApply(apply bool) (checkOK bool, err error) {
+func (obj *PkgRes) CheckApply(apply bool) (bool, error) {
 	obj.init.Logf("Check: %s", obj.fmtNames(obj.getNames()))
 
 	bus := packagekit.NewBus()