Compass: don't save the orientation to EEPROM

there is no point in saving this, the value is only configurable at
compile time for now, and is always set

libraries/AP_Compass/AP_Compass_HMC5843.cpp

@@ -264,7 +264,7 @@ bool AP_Compass_HMC5843::read()
 
    // rotate to the desired orientation
    Vector3f rot_mag = Vector3f(mag_x,mag_y,mag_z);
-   rot_mag.rotate((enum Rotation)_orientation.get());
+   rot_mag.rotate(_orientation);
    if (product_id == AP_COMPASS_TYPE_HMC5883L) {
 	  rot_mag.rotate(ROTATION_YAW_90);
    }
@@ -282,5 +282,5 @@ bool AP_Compass_HMC5843::read()
 void
 AP_Compass_HMC5843::set_orientation(enum Rotation rotation)
 {
-   _orientation.set_and_save(rotation);
+   _orientation = rotation;
 }

libraries/AP_Compass/Compass.cpp

@@ -7,7 +7,6 @@ const AP_Param::GroupInfo Compass::var_info[] PROGMEM = {
     AP_GROUPINFO("DEC",    2, Compass, _declination),
     AP_GROUPINFO("LEARN",  3, Compass, _learn), // true if learning calibration
     AP_GROUPINFO("USE",    4, Compass, _use_for_yaw), // true if used for DCM yaw
-    AP_GROUPINFO("ORIENT", 5, Compass, _orientation),
     AP_GROUPEND
 };
 
@@ -21,9 +20,9 @@ Compass::Compass(void) :
     _learn(1),
     _use_for_yaw(1),
     _null_enable(false),
-    _null_init_done(false)
+    _null_init_done(false),
+    _orientation(ROTATION_NONE)
 {
-    _orientation.set(ROTATION_NONE);
 }
 
 // Default init method, just returns success.
@@ -37,7 +36,7 @@ Compass::init()
 void
 Compass::set_orientation(enum Rotation rotation)
 {
-    _orientation.set_and_save(rotation);
+    _orientation = rotation;
 }
 
 void

libraries/AP_Compass/Compass.h

@@ -119,7 +119,7 @@ public:
     static const struct AP_Param::GroupInfo var_info[];
 
 protected:
-    AP_Int8				_orientation;
+    enum Rotation		_orientation;
 	AP_Vector3f         _offset;
 	AP_Float            _declination;
     AP_Int8             _learn;                 ///<enable calibration learning