Test PSA functions against PSA_SUCCESS, not 0

Writing 0 instead of PSA_SUCCESS is correct, but bad form.
diff --git a/tests/suites/test_suite_cipher.function b/tests/suites/test_suite_cipher.function
index 1ea1408..209d8e4 100644
--- a/tests/suites/test_suite_cipher.function
+++ b/tests/suites/test_suite_cipher.function
@@ -982,7 +982,7 @@
 #else
     if( use_psa == 1 )
     {
-        TEST_ASSERT( psa_crypto_init() == 0 );
+        TEST_ASSERT( psa_crypto_init( ) == PSA_SUCCESS );
 
         /* PSA requires that the tag immediately follows the ciphertext. */
         tmp_cipher = mbedtls_calloc( 1, cipher->len + tag->len );
@@ -1143,7 +1143,7 @@
 #else
     if( use_psa == 1 )
     {
-        TEST_ASSERT( psa_crypto_init() == 0 );
+        TEST_ASSERT( psa_crypto_init( ) == PSA_SUCCESS );
         TEST_ASSERT( 0 == mbedtls_cipher_setup_psa( &ctx,
                               mbedtls_cipher_info_from_type( cipher_id ), 0 ) );
     }
diff --git a/tests/suites/test_suite_pk.function b/tests/suites/test_suite_pk.function
index 3282214..98c5a83 100644
--- a/tests/suites/test_suite_pk.function
+++ b/tests/suites/test_suite_pk.function
@@ -127,7 +127,7 @@
     mbedtls_pk_init( &pk );
     mbedtls_pk_init( &pk2 );
 
-    TEST_ASSERT( psa_crypto_init() == 0 );
+    TEST_ASSERT( psa_crypto_init( ) == PSA_SUCCESS );
 
     TEST_ASSERT( mbedtls_pk_setup_opaque( &pk, 0 ) ==
                  MBEDTLS_ERR_PK_BAD_INPUT_DATA );