Remove all instances of named return "err" from Libpod

This was inspired by https://github.com/cri-o/cri-o/pull/3934 and
much of the logic for it is contained there. However, in brief,
a named return called "err" can cause lots of code confusion and
encourages using the wrong err variable in defer statements,
which can make them work incorrectly. Using a separate name which
is not used elsewhere makes it very clear what the defer should
be doing.

As part of this, remove a large number of named returns that were
not used anywhere. Most of them were once needed, but are no
longer necessary after previous refactors (but were accidentally
retained).

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

1 files changed, 4 insertions, 4 deletions

diff --git a/libpod/state_test.go b/libpod/state_test.go
index 30ddf5e24..ef4f6f2be 100644
--- a/libpod/state_test.go
+++ b/libpod/state_test.go
@@ -34,13 +34,13 @@ var (
 )
 
 // Get an empty BoltDB state for use in tests
-func getEmptyBoltState() (s State, p string, m lock.Manager, err error) {
+func getEmptyBoltState() (_ State, _ string, _ lock.Manager, retErr error) {
 	tmpDir, err := ioutil.TempDir("", tmpDirPrefix)
 	if err != nil {
 		return nil, "", nil, err
 	}
 	defer func() {
-		if err != nil {
+		if retErr != nil {
 			os.RemoveAll(tmpDir)
 		}
 	}()
@@ -66,13 +66,13 @@ func getEmptyBoltState() (s State, p string, m lock.Manager, err error) {
 }
 
 // Get an empty in-memory state for use in tests
-func getEmptyInMemoryState() (s State, p string, m lock.Manager, err error) {
+func getEmptyInMemoryState() (_ State, _ string, _ lock.Manager, retErr error) {
 	tmpDir, err := ioutil.TempDir("", tmpDirPrefix)
 	if err != nil {
 		return nil, "", nil, err
 	}
 	defer func() {
-		if err != nil {
+		if retErr != nil {
 			os.RemoveAll(tmpDir)
 		}
 	}()