Increase matrix library usage even more

EKF/sideslip_fusion.cpp

@@ -263,11 +263,7 @@ void Ekf::fuseSideslip()
 		// only apply covariance and state corrections if healthy
 		if (healthy) {
 			// apply the covariance corrections
-			for (unsigned row = 0; row < _k_num_states; row++) {
-				for (unsigned column = 0; column < _k_num_states; column++) {
-					P(row,column) = P(row,column) - KHP(row,column);
-				}
-			}
+			P -= KHP;
 
 			// correct the covariance matrix for gross errors
 			fixCovarianceErrors(true);