Bluetooth: btrtl: Ignore error return for hci_devcd_register()

If CONFIG_DEV_COREDUMP was not set, it would return -EOPNOTSUPP for
hci_devcd_register().
In this commit, ignore error return for hci_devcd_register().
Otherwise Bluetooth initialization will be failed.

Fixes: 044014ce

 ("Bluetooth: btrtl: Add Realtek devcoredump support")
Cc: stable@vger.kernel.org
Reported-by: Kirill A. Shutemov <kirill@shutemov.name>
Closes: https://lore.kernel.org/all/ZRyqIn0_qqEFBPdy@debian.me/T/


Signed-off-by: Max Chou <max.chou@realtek.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>