Fix mul-by-non-residue for bw6::fq3

bw6_761/src/fields/fq3.rs

@@ -83,6 +83,6 @@ impl Fp3Config for Fq3Config {
 
     #[inline(always)]
     fn mul_fp_by_nonresidue_in_place(fe: &mut Self::Fp) -> &mut Self::Fp {
-        fe.double_in_place().double_in_place()
+        fe.double_in_place().double_in_place().neg_in_place()
     }
 }