Replace compound-initializers with memset

This should eliminate some pedantic compiler warnings.

Signed-off-by: David Horstmann <david.horstmann@arm.com>
diff --git a/tests/suites/test_suite_psa_crypto.function b/tests/suites/test_suite_psa_crypto.function
index d58864f..1dab4e0 100644
--- a/tests/suites/test_suite_psa_crypto.function
+++ b/tests/suites/test_suite_psa_crypto.function
@@ -10442,9 +10442,11 @@
 {
     uint8_t *input_buffer = NULL;
     uint8_t *output_buffer = NULL;
-    psa_crypto_buffer_copy_t buffer_copies = { 0 };
     psa_status_t ret;
 
+    psa_crypto_buffer_copy_t buffer_copies;
+    memset(&buffer_copies, 0, sizeof(buffer_copies));
+
     if (!input_null) {
         TEST_CALLOC(input_buffer, input_len);
         fill_buffer_pattern(input_buffer, input_len);
@@ -10478,11 +10480,12 @@
     uint8_t input_buffer[] = { 0x12 };
     uint8_t output_buffer[] = { 0x34 };
 
-    psa_crypto_buffer_copy_t buffer_copies;
-
     size_t input_len = input_zero_length ? 0 : 1;
     size_t output_len = output_zero_length ? 0 : 1;
 
+    psa_crypto_buffer_copy_t buffer_copies;
+    memset(&buffer_copies, 0, sizeof(buffer_copies));
+
     psa_status_t ret = psa_crypto_alloc_and_copy(input_buffer, input_len,
                                                  output_buffer, output_len,
                                                  &buffer_copies);
@@ -10510,14 +10513,15 @@
 void psa_crypto_alloc_and_copy_overlapping(int input_len, int output_len,
                                            int ptr_diff, int exp_ret)
 {
-    psa_crypto_buffer_copy_t buffer_copies = { 0 };
-
     uint8_t *full_buffer = NULL;
     uint8_t *input = NULL;
     uint8_t *output = NULL;
 
     psa_status_t ret;
 
+    psa_crypto_buffer_copy_t buffer_copies;
+    memset(&buffer_copies, 0, sizeof(buffer_copies));
+
     TEST_EQUAL(setup_overlapping_buffers(input_len, output_len, ptr_diff,
                                          &full_buffer, &input, &output), 0);
 
@@ -10554,8 +10558,6 @@
                               int orig_output_null,
                               int exp_ret)
 {
-    psa_crypto_buffer_copy_t buffer_copies = { 0 };
-
     uint8_t *input = NULL;
     uint8_t *output = NULL;
     uint8_t *output_for_comparison = NULL;
@@ -10563,6 +10565,9 @@
     size_t calloc_len;
     psa_status_t ret;
 
+    psa_crypto_buffer_copy_t buffer_copies;
+    memset(&buffer_copies, 0, sizeof(buffer_copies));
+
     if (!input_null) {
         /* If zero-length, ensure we actually allocate something
          * rather than getting NULL. */
@@ -10622,9 +10627,11 @@
     uint8_t input[100];
     uint8_t output[100];
     uint8_t output_for_comparison[100];
-    psa_crypto_buffer_copy_t buffer_copies = { 0 };
     psa_status_t ret;
 
+    psa_crypto_buffer_copy_t buffer_copies;
+    memset(&buffer_copies, 0, sizeof(buffer_copies));
+
     fill_buffer_pattern(input, sizeof(input));
 
     ret = psa_crypto_alloc_and_copy(input, sizeof(input),