Fix usage of ASSERT_ALLOC()

The second argument is the number of elements of the type the first
argument is pointing to, so we shouldn't be using sizeof there.

This was resulting in overly large allocations.

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
diff --git a/tests/suites/test_suite_asn1parse.function b/tests/suites/test_suite_asn1parse.function
index 87901f8..002d8c4 100644
--- a/tests/suites/test_suite_asn1parse.function
+++ b/tests/suites/test_suite_asn1parse.function
@@ -779,7 +779,7 @@
     for( i = 0; i < length; i++ )
     {
         mbedtls_asn1_named_data *new = NULL;
-        ASSERT_ALLOC( new, sizeof( mbedtls_asn1_named_data ) );
+        ASSERT_ALLOC( new, 1 );
         new->next = head;
         head = new;
     }
diff --git a/tests/suites/test_suite_ssl.function b/tests/suites/test_suite_ssl.function
index 7b5743e..d832853 100644
--- a/tests/suites/test_suite_ssl.function
+++ b/tests/suites/test_suite_ssl.function
@@ -137,7 +137,7 @@
     opts->resize_buffers = 1;
 #if defined(MBEDTLS_SSL_CACHE_C)
     opts->cache = NULL;
-    ASSERT_ALLOC( opts->cache, sizeof( mbedtls_ssl_cache_context ) );
+    ASSERT_ALLOC( opts->cache, 1 );
     mbedtls_ssl_cache_init( opts->cache );
 exit:
     return;