[sk] Make asset creation stream logs to stdout

The existing setup would only print the logs after asset creation
errored out (and not in the successful case).

For long-running creation scripts, we should show the user what is
happening.

Change-Id: Iff8440bc3d870a4abbf6f87c541a443b0cbacd6d
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/584156
Reviewed-by: Ravi Mistry <rmistry@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
diff --git a/sk/go/asset/BUILD.bazel b/sk/go/asset/BUILD.bazel
index 090519b..5d6eb41 100644
--- a/sk/go/asset/BUILD.bazel
+++ b/sk/go/asset/BUILD.bazel
@@ -8,7 +8,6 @@
     deps = [
         "//go/auth",
         "//go/cipd",
-        "//go/exec",
         "//go/git",
         "//go/httputils",
         "//go/luciauth",
diff --git a/sk/go/asset/asset.go b/sk/go/asset/asset.go
index 5fb904f..ae20c7d 100644
--- a/sk/go/asset/asset.go
+++ b/sk/go/asset/asset.go
@@ -8,6 +8,7 @@
 	"io"
 	"io/ioutil"
 	"os"
+	os_exec "os/exec"
 	"path/filepath"
 	"regexp"
 	"sort"
@@ -24,7 +25,6 @@
 
 	"go.skia.org/infra/go/auth"
 	"go.skia.org/infra/go/cipd"
-	"go.skia.org/infra/go/exec"
 	"go.skia.org/infra/go/git"
 	"go.skia.org/infra/go/httputils"
 	"go.skia.org/infra/go/luciauth"
@@ -370,15 +370,11 @@
 				rvErr = err
 			}
 		}()
-		cmd := &exec.Command{
-			Name:      "python",
-			Args:      []string{"-u", creationScript, "-t", src},
-			Dir:       ".",
-			LogStdout: true,
-			LogStderr: true,
-		}
-		fmt.Println(fmt.Sprintf("Running: %s %s", cmd.Name, strings.Join(cmd.Args, " ")))
-		if err := exec.Run(ctx, cmd); err != nil {
+		cmd := os_exec.CommandContext(ctx, "python", "-u", creationScript, "-t", src)
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		fmt.Println(fmt.Sprintf("Running: %s %s", cmd.Path, strings.Join(cmd.Args, " ")))
+		if err := cmd.Run(); err != nil {
 			return skerr.Wrap(err)
 		}
 		fmt.Println("Finished running asset creation script.")