Bluetooth: Fix compile warnings in mgmt

Commit af7985bf85840e3dc90ba108a679db044f91f00e introduced regression
resulting in complie warnings:

...
net/bluetooth/mgmt.c:3568:27: warning: invalid assignment: |=
net/bluetooth/mgmt.c:3568:27:    left side has type restricted __le32
net/bluetooth/mgmt.c:3568:27:    right side has type int
net/bluetooth/mgmt.c:3570:27: warning: invalid assignment: |=
net/bluetooth/mgmt.c:3570:27:    left side has type restricted __le32
net/bluetooth/mgmt.c:3570:27:    right side has type int
net/bluetooth/mgmt.c:3580:21: warning: cast from restricted __le32
...

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>