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, 1 insertions, 1 deletions

diff --git a/libpod/container_internal_unsupported.go b/libpod/container_internal_unsupported.go
index a42c1d735..e6d94104c 100644
--- a/libpod/container_internal_unsupported.go
+++ b/libpod/container_internal_unsupported.go
@@ -18,7 +18,7 @@ func (c *Container) unmountSHM(mount string) error {
 	return define.ErrNotImplemented
 }
 
-func (c *Container) prepare() (err error) {
+func (c *Container) prepare() error {
 	return define.ErrNotImplemented
 }