Do not cast to const type, when not required

Signed-off-by: Anjan Roy <hello@itzmeanjan.in>

Author: itzmeanjan

include/ml_kem/internals/ml_kem.hpp

@@ -148,9 +148,8 @@ decapsulate(std::span<const uint8_t, ml_kem_utils::get_kem_secret_key_len(k)> se
   (void)k_pke::encrypt<k, eta1, eta2, du, dv>(pubkey, g_in_span0, g_out_span1, c_prime);
 
   // line 9-12 of algorithm 17, in constant-time
-  using kdf_t = std::span<const uint8_t, shared_secret.size()>;
   const uint32_t cond = ml_kem_utils::ct_memcmp(cipher, std::span<const uint8_t, ctlen>(c_prime));
-  ml_kem_utils::ct_cond_memcpy(cond, shared_secret, kdf_t(g_out_span0), kdf_t(z));
+  ml_kem_utils::ct_cond_memcpy(cond, shared_secret, std::span<const uint8_t, g_out_span0.size()>(g_out_span0), z);
 }
 
 }