explicitly set filesystem type for mount to avoid 'invalid argument' error on arm

Signed-off-by: Jim Ehrismann <jim.ehrismann@docker.com>

integration-cli/docker_cli_daemon_test.go

@@ -1715,7 +1715,7 @@ func (s *DockerDaemonSuite) TestDaemonNoSpaceLeftOnDeviceError(c *check.C) {
 	dockerCmd(c, "run", "--rm", "-v", testDir+":/test", "busybox", "sh", "-c", "dd of=/test/testfs.img bs=1M seek=3 count=0")
 	icmd.RunCommand("mkfs.ext4", "-F", filepath.Join(testDir, "testfs.img")).Assert(c, icmd.Success)
 
-	dockerCmd(c, "run", "--privileged", "--rm", "-v", testDir+":/test:shared", "busybox", "sh", "-c", "mkdir -p /test/test-mount/vfs && mount -n /test/testfs.img /test/test-mount/vfs")
+	dockerCmd(c, "run", "--privileged", "--rm", "-v", testDir+":/test:shared", "busybox", "sh", "-c", "mkdir -p /test/test-mount/vfs && mount -n -t ext4 /test/testfs.img /test/test-mount/vfs")
 	defer mount.Unmount(filepath.Join(testDir, "test-mount"))
 
 	s.d.Start(c, "--storage-driver", "vfs", "--data-root", filepath.Join(testDir, "test-mount"))