Add a workaround for max test suite parameter sizes

int isn't enough for SIZE_MAX/2.
Hardcoding the value will make the compilers complain.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/tests/suites/test_suite_debug.function b/tests/suites/test_suite_debug.function
index 617dd88..34e006f 100644
--- a/tests/suites/test_suite_debug.function
+++ b/tests/suites/test_suite_debug.function
@@ -200,7 +200,7 @@
 void check_mbedtls_calloc_overallocation(int num, int size)
 {
     unsigned char *buf;
-    buf = mbedtls_calloc((size_t) num, (size_t) size);
+    buf = mbedtls_calloc((size_t) num * SIZE_MAX/2, (size_t) size * SIZE_MAX/2);
     /* Dummy usage of the pointer to prevent optimizing it */
     mbedtls_printf("calloc pointer : %p\n", buf);
     TEST_ASSERT(buf == NULL);