AP_NavEKF3: simplify logic when updating yawAngDataStatic

libraries/AP_NavEKF3/AP_NavEKF3_MagFusion.cpp

@@ -208,13 +208,10 @@ void NavEKF3_core::SelectMagFusion()
         if (fabsf(prevTnb[0][2]) < fabsf(prevTnb[1][2])) {
             // A 321 rotation order is best conditioned because the X axis is closer to horizontal than the Y axis
             yawAngDataStatic.order = rotationOrder::TAIT_BRYAN_321;
+            yawAngDataStatic.yawAng = atan2f(prevTnb[0][1], prevTnb[0][0]);
         } else {
             // A 312 rotation order is best conditioned because the Y axis is closer to horizontal than the X axis
             yawAngDataStatic.order = rotationOrder::TAIT_BRYAN_312;
-        }
-        if (yawAngDataStatic.order == rotationOrder::TAIT_BRYAN_321) {
-            yawAngDataStatic.yawAng = atan2f(prevTnb[0][1], prevTnb[0][0]);
-        } else if (yawAngDataStatic.order == rotationOrder::TAIT_BRYAN_312) {
             yawAngDataStatic.yawAng = atan2f(-prevTnb[1][0], prevTnb[1][1]);
         }
         yawAngDataStatic.yawAngErr = MAX(frontend->_yawNoise, 0.05f);