Copter: add parenthesis around ntun log bitmask

Resolves one compiler warning
Inav_EKF: bug fix to init member
AC_Sprayer: append f to floating point constants

Reduces some compiler warnings
Compass: bug fix to init of device id

Also init members to reduce compiler warnings
AP_Airspeed: use 'no break' to resolve compiler warning re switch
AP_Airspeed: init members to reduce compiler warnings
Camera: remove unused reference to hal

Resolves one compiler warning
AP_InertialSensor: init members to reduce compiler warnings
AP_InertialSensor_MPU6k: init members to reduce compiler warnings