Fix type of GPU thread's input buffer

The input buffer for paper_gpu_thread is a paper_gpu_input_databuf_t,
NOT a paper_input_databuf_t.  Looks like it was a silly copy and paste
error.
Update hashpipe_check_status name in paper_ctl.sh

The hashpipe_check_status utility used to be called
check_hashpipe_status.
Change default intcount to 2048 blocks

This leads to ~10.7 second integrations:

   2048 samples per spectra
x   512 spectra per block
x  2048 blocks  per integration
/ 200e6 samples per second
===================================
10.73741824 seconds per integration
Fix definition of paper_input_databuf_data_idx

This adds a factor that was missing from the calculation.
Fix p_out calculation in paper_fluff

This adds a term that was missing from the calculation.