Improve error messages when Java commands fail (#1464)

When we fail to execute a Java command, we currently duplicate the
command name (e.g. `mvn`), which makes it harder to understand what has
gone wrong. This commit cleans this up, additionally quoting the command
we attempted to run so that it's easier to parse in the event it
contains spaces.

pkg/cmd/pulumi-language-java/command.go

@@ -11,7 +11,6 @@ import (
 
 // Like `cmd.Run()` but issues friendlier errors.
 func runCommand(cmd *exec.Cmd) error {
-	name := cmd.Path
 	commandStr := strings.Join(cmd.Args, " ")
 	if err := cmd.Run(); err != nil {
 		if exiterr, ok := err.(*exec.ExitError); ok {
@@ -20,16 +19,16 @@ func runCommand(cmd *exec.Cmd) error {
 			// So, the error message should look as nice as possible.
 			if status, stok := exiterr.Sys().(syscall.WaitStatus); stok {
 				code := status.ExitStatus()
-				return fmt.Errorf("'%v %v' exited with non-zero exit code: %d", name, commandStr, code)
+				return fmt.Errorf("'%v' exited with non-zero exit code: %d", commandStr, code)
 			}
-			return fmt.Errorf("'%v %v' exited unexpectedly: %w", name, commandStr, exiterr)
+			return fmt.Errorf("'%v' exited unexpectedly: %w", commandStr, exiterr)
 		}
 
 		// Otherwise, we didn't even get to run the program.
 		// This ought to never happen unless there's a bug or
 		// system condition that prevented us from running the
 		// language exec. Issue a scarier error.
-		return fmt.Errorf("Problem executing '%v %v': %w", name, commandStr, err)
+		return fmt.Errorf("Problem executing '%v': %w", commandStr, err)
 	}
 	return nil
 }