tools: kwbimage: Fix printf format warning

On 32-bit ARM the compiler complains:
  tools/kwbimage.c:547: warning: format ‘%lu’ expects argument of type
                                 ‘long unsigned int’, but argument 4 has
		                 type ‘unsigned int’

Fix this by using %zu instead of %lu format specifier.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>
1 file changed