Return error code when volume inspect fails with a template.

Following `docker inspect` conventions:

- Keep partial info in a buffer to not print incomplete template outputs.
- Break execution when template parsing or decoding fail.

Signed-off-by: David Calavera <david.calavera@gmail.com>

integration-cli/docker_cli_volume_test.go

@@ -165,3 +165,13 @@ func (s *DockerSuite) TestVolumeCliNoArgs(c *check.C) {
 	c.Assert(stderr, checker.Contains, usage)
 	c.Assert(stderr, checker.Contains, "flag provided but not defined: --no-such-flag")
 }
+
+func (s *DockerSuite) TestVolumeCliInspectTmplError(c *check.C) {
+	out, _ := dockerCmd(c, "volume", "create")
+	name := strings.TrimSpace(out)
+
+	out, exitCode, err := dockerCmdWithError("volume", "inspect", "--format='{{ .FooBar }}'", name)
+	c.Assert(err, checker.NotNil, check.Commentf("Output: %s", out))
+	c.Assert(exitCode, checker.Equals, 1, check.Commentf("Output: %s", out))
+	c.Assert(out, checker.Contains, "Template parsing error")
+}