Clearer variable names

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/suites/test_suite_pk.function b/tests/suites/test_suite_pk.function
index 7969d22..3d7a179 100644
--- a/tests/suites/test_suite_pk.function
+++ b/tests/suites/test_suite_pk.function
@@ -1850,8 +1850,8 @@
 /* END_CASE */
 
 /* BEGIN_CASE depends_on:MBEDTLS_USE_PSA_CRYPTO */
-void pk_get_psa_attributes_opaque(int o_type_arg, int o_bits_arg,
-                                  int o_usage_arg, int o_alg_arg,
+void pk_get_psa_attributes_opaque(int from_type_arg, int from_bits_arg,
+                                  int from_usage_arg, int from_alg_arg,
                                   int usage_arg,
                                   int expected_ret,
                                   int to_pair, int expected_usage_arg)
@@ -1860,18 +1860,18 @@
     mbedtls_pk_init(&pk);
     psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
     mbedtls_svc_key_id_t key_id = MBEDTLS_SVC_KEY_ID_INIT;
-    psa_key_type_t o_type = o_type_arg;
-    size_t bits = o_bits_arg;
-    psa_key_usage_t o_usage = o_usage_arg;
-    psa_algorithm_t alg = o_alg_arg;
+    psa_key_type_t from_type = from_type_arg;
+    size_t bits = from_bits_arg;
+    psa_key_usage_t from_usage = from_usage_arg;
+    psa_algorithm_t alg = from_alg_arg;
     psa_key_usage_t usage = usage_arg;
     psa_key_usage_t expected_usage = expected_usage_arg;
 
     PSA_INIT();
 
-    psa_set_key_type(&attributes, o_type);
+    psa_set_key_type(&attributes, from_type);
     psa_set_key_bits(&attributes, bits);
-    psa_set_key_usage_flags(&attributes, o_usage);
+    psa_set_key_usage_flags(&attributes, from_usage);
     psa_set_key_algorithm(&attributes, alg);
     psa_set_key_enrollment_algorithm(&attributes, 42);
     //TODO: test with persistent key
@@ -1879,7 +1879,7 @@
     TEST_EQUAL(mbedtls_pk_setup_opaque(&pk, key_id), 0);
 
     psa_key_type_t expected_psa_type =
-        to_pair ? o_type : PSA_KEY_TYPE_PUBLIC_KEY_OF_KEY_PAIR(o_type);
+        to_pair ? from_type : PSA_KEY_TYPE_PUBLIC_KEY_OF_KEY_PAIR(from_type);
 
     TEST_EQUAL(mbedtls_pk_get_psa_attributes(&pk, usage, &attributes),
                expected_ret);