check_config/block_cipher: minor improvements

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/include/mbedtls/check_config.h b/include/mbedtls/check_config.h
index 30ef7d6..3b39c91 100644
--- a/include/mbedtls/check_config.h
+++ b/include/mbedtls/check_config.h
@@ -334,16 +334,14 @@
 #undef MBEDTLS_HAS_MEMSAN
 
 #if defined(MBEDTLS_CCM_C) && \
-    !(defined(MBEDTLS_BLOCK_CIPHER_CAN_AES) || defined(MBEDTLS_AES_C) || \
-    defined(MBEDTLS_BLOCK_CIPHER_CAN_ARIA) || defined(MBEDTLS_ARIA_C) || \
-    defined(MBEDTLS_BLOCK_CIPHER_CAN_CAMELLIA) || defined(MBEDTLS_CAMELLIA_C))
+    !(defined(MBEDTLS_CCM_GCM_CAN_AES) || defined(MBEDTLS_CCM_GCM_CAN_ARIA) || \
+    defined(MBEDTLS_CCM_GCM_CAN_CAMELLIA))
 #error "MBEDTLS_CCM_C defined, but not all prerequisites"
 #endif
 
 #if defined(MBEDTLS_GCM_C) && \
-    !(defined(MBEDTLS_BLOCK_CIPHER_CAN_AES) || defined(MBEDTLS_AES_C) || \
-    defined(MBEDTLS_BLOCK_CIPHER_CAN_ARIA) || defined(MBEDTLS_ARIA_C) || \
-    defined(MBEDTLS_BLOCK_CIPHER_CAN_CAMELLIA) || defined(MBEDTLS_CAMELLIA_C))
+    !(defined(MBEDTLS_CCM_GCM_CAN_AES) || defined(MBEDTLS_CCM_GCM_CAN_ARIA) || \
+    defined(MBEDTLS_CCM_GCM_CAN_CAMELLIA))
 #error "MBEDTLS_GCM_C defined, but not all prerequisites"
 #endif
 
diff --git a/library/block_cipher.c b/library/block_cipher.c
index bfb605e..e21541e 100644
--- a/library/block_cipher.c
+++ b/library/block_cipher.c
@@ -42,7 +42,7 @@
     }
 }
 
-int mbedtls_cipher_error_from_psa(psa_status_t status)
+static int mbedtls_cipher_error_from_psa(psa_status_t status)
 {
     return PSA_TO_MBEDTLS_ERR_LIST(status, psa_to_cipher_errors,
                                    psa_generic_status_to_mbedtls);