cherenkov/rankingstat.py: edit some comments

gstlal-burst/python/cherenkov/rankingstat.py

@@ -110,6 +110,9 @@ class LnSignalDensity(snglcoinc.LnLRDensity):
 		xml.appendChild(ligolw_param.Param.from_pyvalue("instruments", lsctables.instrumentsproperty.set(self.instruments)))
 		xml.appendChild(ligolw_param.Param.from_pyvalue("delta_t", self.delta_t))
 		xml.appendChild(ligolw_param.Param.from_pyvalue("min_instruments", self.min_instruments))
+		# FIXME:  the other PDF parameters aren't saved, so when
+		# loaded it always gets whatever the class defines them to
+		# be.  is this OK?
 		return xml
 
 	@classmethod
@@ -448,7 +451,7 @@ class RankingStatPDF(object):
 			print("done computing ranking statistic PDFs", file=sys.stderr)
 
 		#
-		# apply density estimation kernels to counts
+		# apply density estimation kernel to noise model counts
 		#
 
 		self.density_estimate(self.noise_lr_lnpdf, "noise model")