migration: Fix order of function arguments

migration: Fix order of function arguments

This fixes a compiler error when higher warning levels are enabled:

../migration/postcopy-ram.c: In function ‘postcopy_temp_pages_setup’:
../migration/postcopy-ram.c:1483:50: error: ‘g_malloc0_n’ sizes specified with ‘sizeof’ in the earlier argument and not in the later argument [-Werror=calloc-transposed-args]
 1483 |     mis->postcopy_tmp_pages = g_malloc0_n(sizeof(PostcopyTmpPage), channels);
      |                                                  ^~~~~~~~~~~~~~~
../migration/postcopy-ram.c:1483:50: note: earlier argument should specify number of elements, later size of each element

Avoid also a related int/unsigned mismatch by fixing the type of
two local variables.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20251209125049.764095-1-sw@weilnetz.de>
[PMD: Replace g_malloc0_n() by g_new0()]
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Peter Xu <peterx@redhat.com>
Message-Id: <20251209195010.83219-1-philmd@linaro.org>