Fixed bug in est_map_ri8self, hmm_ri8self.c

Expansion and contraction on lines 130 and 137 of hmm_ri8self.c should cancel, but don't.
Line 130 may have been incorrectly copied from "R = ..." just below
Equation (1), page 3, in Teuscher and Broman, "Haplotype Probabilities for Multiple-Strain Recombinant Inbred Lines"