pkg/pidfile: remove named err-returns

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

pkg/pidfile/pidfile.go

@@ -17,7 +17,7 @@ import (
 // failing to read the file, or if the file doesn't exist, but malformed content
 // is ignored. Consumers should therefore check if the returned PID is a non-zero
 // value before use.
-func Read(path string) (pid int, err error) {
+func Read(path string) (pid int, _ error) {
 	pidByte, err := os.ReadFile(path)
 	if err != nil {
 		return 0, err