Convert interruptible test over to using TEST_CALLOC

Also fix potential leak in unlikely edge case.

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
diff --git a/tests/suites/test_suite_psa_crypto.function b/tests/suites/test_suite_psa_crypto.function
index 2dfc7a4..a510f8e 100644
--- a/tests/suites/test_suite_psa_crypto.function
+++ b/tests/suites/test_suite_psa_crypto.function
@@ -7639,8 +7639,7 @@
      * no reliance on external buffers. */
     psa_interruptible_set_max_ops(PSA_INTERRUPTIBLE_MAX_OPS_UNLIMITED);
 
-    input_buffer = mbedtls_calloc(1, input_data->len);
-    TEST_ASSERT(input_buffer != NULL);
+    TEST_CALLOC(input_buffer, input_data->len);
 
     memcpy(input_buffer, input_data->x, input_data->len);
 
@@ -7657,8 +7656,7 @@
 
     PSA_ASSERT(psa_sign_hash_abort(&sign_operation));
 
-    input_buffer = mbedtls_calloc(1, input_data->len);
-    TEST_ASSERT(input_buffer != NULL);
+    TEST_CALLOC(input_buffer, input_data->len);
 
     memcpy(input_buffer, input_data->x, input_data->len);
 
@@ -7683,6 +7681,7 @@
 
     psa_destroy_key(key);
     mbedtls_free(signature);
+    mbedtls_free(input_buffer);
     PSA_DONE();
 }
 /* END_CASE */