AC_Circle: init members and flags

Removed unused dir flag
Resolves Coverity warning

libraries/AC_WPNav/AC_Circle.cpp

@@ -35,6 +35,7 @@ AC_Circle::AC_Circle(const AP_InertialNav& inav, const AP_AHRS& ahrs, AC_PosCont
     _inav(inav),
     _ahrs(ahrs),
     _pos_control(pos_control),
+    _last_update(0),
     _yaw(0.0f),
     _angle(0.0f),
     _angle_total(0.0f),
@@ -43,6 +44,9 @@ AC_Circle::AC_Circle(const AP_InertialNav& inav, const AP_AHRS& ahrs, AC_PosCont
     _angular_accel(0.0f)
 {
     AP_Param::setup_object_defaults(this, var_info);
+
+    // init flags
+    _flags.panorama = false;
 }
 
 /// init - initialise circle controller setting center specifically

libraries/AC_WPNav/AC_Circle.h

@@ -78,7 +78,6 @@ private:
     // flags structure
     struct circle_flags {
         uint8_t panorama    : 1;    // true if we are doing a panorama
-        uint8_t dir         : 1;    // 0 = clockwise, 1 = counter clockwise
     } _flags;
 
     // references to inertial nav and ahrs libraries