Fix use of sizeof without brackets

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/tests/suites/test_suite_x509parse.function b/tests/suites/test_suite_x509parse.function
index 5d896bf..b522c1a 100644
--- a/tests/suites/test_suite_x509parse.function
+++ b/tests/suites/test_suite_x509parse.function
@@ -1217,9 +1217,9 @@
 
     /* Load a chain with nb_int intermediates (from 01 to nb_int),
      * plus one "end-entity" cert (nb_int + 1) */
-    ret = mbedtls_snprintf(file_buf, sizeof file_buf, "%s/c%02d.pem", chain_dir,
+    ret = mbedtls_snprintf(file_buf, sizeof(file_buf), "%s/c%02d.pem", chain_dir,
                            nb_int + 1);
-    TEST_ASSERT(ret > 0 && (size_t) ret < sizeof file_buf);
+    TEST_ASSERT(ret > 0 && (size_t) ret < sizeof(file_buf));
     TEST_ASSERT(mbedtls_x509_crt_parse_file(&chain, file_buf) == 0);
 
     /* Try to verify that chain */
@@ -1312,13 +1312,13 @@
     mbedtls_x509_buf oid;
     char num_buf[100];
 
-    memset(num_buf, 0x2a, sizeof num_buf);
+    memset(num_buf, 0x2a, sizeof(num_buf));
 
     oid.tag = MBEDTLS_ASN1_OID;
     oid.p   = oid_buf->x;
     oid.len   = oid_buf->len;
 
-    TEST_ASSERT((size_t) blen <= sizeof num_buf);
+    TEST_ASSERT((size_t) blen <= sizeof(num_buf));
 
     TEST_ASSERT(mbedtls_oid_get_numeric_string(num_buf, blen, &oid) == ret);