iwlwifi: fix compilation warning in 'iwl-4965.c'

This patch fixes a compilation warning in 'iwl-4965.c'.

"warning: format ‘%d’ expects type ‘int’, but argument 3 has type ‘long unsigned int’"

Signed-off-by: Miguel Botón <mboton@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>