Test suites: cope with psa_crypto_init failure

psa_crypto_init() can fail. Do check its return code. Don't call it
before initializing local objects that are going to be cleaned up.
diff --git a/tests/suites/test_suite_pk.function b/tests/suites/test_suite_pk.function
index d85d9ed..3282214 100644
--- a/tests/suites/test_suite_pk.function
+++ b/tests/suites/test_suite_pk.function
@@ -124,11 +124,11 @@
     size_t len;
     mbedtls_pk_debug_item dbg;
 
-    TEST_ASSERT( psa_crypto_init() == 0 );
-
     mbedtls_pk_init( &pk );
     mbedtls_pk_init( &pk2 );
 
+    TEST_ASSERT( psa_crypto_init() == 0 );
+
     TEST_ASSERT( mbedtls_pk_setup_opaque( &pk, 0 ) ==
                  MBEDTLS_ERR_PK_BAD_INPUT_DATA );