Fix mismerge that crept into r301289.

The conversion of 0 -> NULL required a rebase at some point, as noted
in r301289 when pfg commited it. In that rebase, three lines remained
that had been removed in a prior version of awk, and one of them had a
0 -> NULL change causing a conflict. The conflict should have been
resolved by removing the three lines, but wasn't. This introduces a
regression into f.split3 test which prior to this commit we were
failing, but a pure onetrueawk wasn't. Remove the offending 3 lines.

contrib/one-true-awk/run.c

@@ -1387,9 +1387,6 @@ Cell *split(Node **a, int nnn)	/* split(a[0], a[1], a[2]); a[3] is type */
 	tempfree(y);
 	free(origs);
 	free(origfs);
-	if (a[2] != NULL && arg3type == STRING) {
-		tempfree(x);
-	}
 	x = gettemp();
 	x->tval = NUM;
 	x->fval = n;