Fix compile issue on Linux/WSL

Author: tridelat

include/hydroc/wave_types.h

@@ -361,7 +361,7 @@ class IrregularWaves : public WaveBase {
 
     /** @brief Calculates width (used for excitation convolution).
      */
-    void IrregularWaves::CalculateWidthIRF();
+    void CalculateWidthIRF();
 
     /**
      * @brief Calculates the component of force from Convolution integral for specified body, dof, time.
@@ -410,4 +410,4 @@ std::vector<std::array<size_t, 3>> CreateFreeSurfaceTriangles(size_t eta_size);
  */
 std::vector<std::array<double, 3>> CreateFreeSurface3DPts(const Eigen::VectorXd& eta, const Eigen::VectorXd& t_vec);
 
-#endif
+#endif