Vector: fix cf to cs conjugate conversion

lib/src/phy/utils/test/vector_test.c

@@ -414,7 +414,7 @@ TEST(
 
     short gold_re;
     short gold_im;
-    for (int i = 0; i < block_size; i++) { x[i] = (float)RANDOM_CF(); }
+    for (int i = 0; i < block_size; i++) { x[i] = RANDOM_CF(); }
 
     TEST_CALL(srslte_vec_convert_conj_cs(x, scale, z, block_size))
 

lib/src/phy/utils/vector_simd.c

@@ -513,7 +513,9 @@ void srslte_vec_convert_conj_cs_simd(const cf_t* x_, int16_t* z, const float sca
 #endif /* SRSLTE_SIMD_F_SIZE && SRSLTE_SIMD_S_SIZE */
 
   for (; i < len; i++) {
-    z[i] = (int16_t)(conjf(x[i]) * scale);
+    z[i] = (int16_t)(x[i] * scale);
+    i++;
+    z[i] = (int16_t)(x[i] * -scale);
   }
 }