efl gfx_path: fix memory leak.

his reverts commit 38be95b0b6fd93df01636ae0a7c974b32ed694a1.

The reverting patch blocks efl_canvas_vg_shape triggers efl_canvas_vg_node destructor.

That occurs massive leaks among the all nodes in the vector tree.

To fix the origin issue, we must reset path explicitly in the derived class.

@fix