Bluetooth: missed cpu_to_le16 conversion in hci_init4_req

It looks like in hci_init4_req() the request is being
initialised from cpu-endian data but the packet is specified
to be little-endian. This causes an warning from sparse due
to __le16 to u16 conversion.

Fix this by using cpu_to_le16() on the two fields in the packet.

net/bluetooth/hci_core.c:845:27: warning: incorrect type in assignment (different base types)
net/bluetooth/hci_core.c:845:27:    expected restricted __le16 [usertype] tx_len
net/bluetooth/hci_core.c:845:27:    got unsigned short [usertype] le_max_tx_len
net/bluetooth/hci_core.c:846:28: warning: incorrect type in assignment (different base types)
net/bluetooth/hci_core.c:846:28:    expected restricted __le16 [usertype] tx_time
net/bluetooth/hci_core.c:846:28:    got unsigned short [usertype] le_max_tx_time

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>