fix logic when not creating a workdir

When resolving the workdir of a container, we may need to create unless
the user set it explicitly on the command line.  Otherwise, we just do a
presence check.  Unfortunately, there was a missing return that lead us
to fall through into attempting to create and chown the workdir.  That
caused a regression when running on a read-only root fs.

Fixes: #9230
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

libpod/container_internal_linux.go

@@ -213,6 +213,7 @@ func (c *Container) resolveWorkDir() error {
 			// we need to return the full error.
 			return errors.Wrapf(err, "error detecting workdir %q on container %s", workdir, c.ID())
 		}
+		return nil
 	}
 
 	// Ensure container entrypoint is created (if required).