archive: report error from input stream

if there is an error reading from the input stream, prefer to report
it instead of the error from the filter program itself.

We have a test in the buildah CI that expects the "no space left on
device" error that comes from the input stream, to avoid changing the
test, just fix it here.

Reported here: containers/buildah#5585

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

pkg/archive/filter.go

@@ -46,7 +46,14 @@ func tryProcFilter(args []string, input io.Reader, cleanup func()) (io.ReadClose
 	go func() {
 		err := cmd.Run()
 		if err != nil && stderrBuf.Len() > 0 {
-			err = fmt.Errorf("%s: %w", strings.TrimRight(stderrBuf.String(), "\n"), err)
+			b := make([]byte, 0)
+			// if there is an error reading from input, prefer to return that error
+			_, errRead := input.Read(b)
+			if errRead != nil {
+				err = errRead
+			} else {
+				err = fmt.Errorf("%s: %w", strings.TrimRight(stderrBuf.String(), "\n"), err)
+			}
 		}
 		w.CloseWithError(err) // CloseWithErr(nil) == Close()
 		cleanup()