thunk: improve readability of allocation loop

Signed-off-by: Aarushi Mehta <mehta.aaru20@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <a09acf9e093c09a70896bb9886370cf7f049f941.camel@gmail.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

thunk.c

@@ -86,7 +86,7 @@ void thunk_register_struct(int id, const char *name, const argtype *types)
 #endif
     /* now we can alloc the data */
 
-    for(i = 0;i < 2; i++) {
+    for (i = 0; i < ARRAY_SIZE(se->field_offsets); i++) {
         offset = 0;
         max_align = 1;
         se->field_offsets[i] = g_new(int, nb_fields);