Slight underestimate of the pairlist buffer on Intel GPUs
The GPU kernel setup incorrectly ignored the split of the j-cluster in two halves. Apart from incorrect prints to the log file, this only affected the pairlist buffer on Intel GPUs, which use a 4x2 kernel setup.
Fix too small pairlist buffer on Intel GPUs
The pairlist buffer generated for Intel GPUs was slightly too small,
because it assumed a 4x4 atom-cluster pair kernel instead of 4x2.
This also fixes incorrect kernel setup messages in the log file.