staging: vme: fix bare use of 'unsigned'

fix checkpatch.pl warning about 'Prefer 'unsigned int' to bare use of
'unsigned''

Signed-off-by: Clifton Barnes <clifton.a.barnes@gmail.com>
Acked-by: Martyn Welch <martyn@welchs.me.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>