Delete conditional push back in the function vector and fix white screen

[Hpn4]

Change in the pipe:

• After a batch has arrived, the pipe now wait for time stride before doing spatial transformation and following computation
• After the spatial transformation, the pipe now wait for the time transformation queue to be full before doing calculation (before computation where done on it when not full so made on not initialized data resulting in Nan values and a white screen)

Also the float_to_complex kernel have been deleted since not used