Fix stutters

Podman adds an Error: to every error message.  So starting an error
message with "error" ends up being reported to the user as

Error: error ...

This patch removes the stutter.

Also ioutil.ReadFile errors report the Path, so wrapping the err message
with the path causes a stutter.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

pkg/parallel/parallel.go

@@ -60,7 +60,7 @@ func Enqueue(ctx context.Context, fn func() error) <-chan error {
 		defer close(retChan)
 
 		if err := jobControl.Acquire(ctx, 1); err != nil {
-			retChan <- fmt.Errorf("error acquiring job control semaphore: %w", err)
+			retChan <- fmt.Errorf("acquiring job control semaphore: %w", err)
 			return
 		}