Fix copypasta

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/include/psa/crypto_extra.h b/include/psa/crypto_extra.h
index b36ec6f..0e78989 100644
--- a/include/psa/crypto_extra.h
+++ b/include/psa/crypto_extra.h
@@ -622,7 +622,7 @@
  * \param key_type    The key type.
  * \param cipher_alg  The cipher algorithm.
  *
- * \return 1 if the PSA can handle \p hash_alg, 0 otherwise.
+ * \return 1 if the PSA can handle \p cipher_alg, 0 otherwise.
  */
 int psa_can_do_cipher(psa_key_type_t key_type, psa_algorithm_t cipher_alg);