tty: rpmsg: Use dev_err_probe() in ->probe()

It's fine to use dev_err_probe() in ->probe() even if we know
it won't be deferred.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211025135148.53944-3-andriy.shevchenko@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>