The question here is whether the third which, referring to the evil spirit, should have also been edited to who (just as two preceding instances of which were). Generally, in the current Book of Mormon text the noun devil takes the relative pronoun who (six times)—although in the earliest text, five of these instances of who read as which. The text has only two examples of evil spirit followed by a relative pronoun, and that pronoun is which in both the original and the current text:
Thus Joseph Smith’s editing is consistent in leaving the which unedited when the antecedent is the evil spirit (although there are only these two examples). The critical text here will, of course, maintain all the instances of original which, both with devil and evil spirit (as well as with master of sin, which occurs only once in the text—here in Mosiah 4:14). For a complete discussion, see under which in volume 3.
Summary: Retain the relative pronoun which that refers to “the evil spirit” in Mosiah 4:14 as well as in Mosiah 2:32; the critical text will consistently restore all instances of original which.