Bluetooth: hci_core: Fix possible buffer overflow

struct hci_dev_info has a fixed size name[8] field so in the event that
hdev->name is bigger than that strcpy would attempt to write past its
size, so this fixes this problem by switching to use strscpy.

Fixes: dcda1657 ("Bluetooth: hci_core: Fix build warnings")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>