remove unnecessary if in kyber768

clang-tidy9.0.0 added a new check: bugprone-branch-clone
(https://releases.llvm.org/9.0.0/tools/clang/tools/extra/docs/ReleaseNotes.html)
This doesn't like both branches of an if are the same.
In this case I don't think there is any reason to do this, so I've removed it.

crypto_kem/kyber768/avx2/indcpa.c

@@ -199,11 +199,7 @@ static void gen_matrix(polyvec *a, const uint8_t *seed, int transposed) {
     PQCLEAN_KYBER768_AVX2_poly_nttunpack(&a[2].vec[0]);
     PQCLEAN_KYBER768_AVX2_poly_nttunpack(&a[2].vec[1]);
 
-    if (transposed) {
-        PQCLEAN_KYBER768_AVX2_kyber_shake128_absorb(&state1x, seed, 2, 2);
-    } else {
-        PQCLEAN_KYBER768_AVX2_kyber_shake128_absorb(&state1x, seed, 2, 2);
-    }
+    PQCLEAN_KYBER768_AVX2_kyber_shake128_absorb(&state1x, seed, 2, 2);
 
     PQCLEAN_KYBER768_AVX2_kyber_shake128_squeezeblocks(buf.x[0], GEN_MATRIX_MAXNBLOCKS, &state1x);
     bufbytes = GEN_MATRIX_MAXNBLOCKS * XOF_BLOCKBYTES;