staging: comedi: mite: remove BUG_ON() in MITE_IODWBSR_1_WSIZE_bits()

Prior to calling this function pci_ioremap_bar() is called. If the
pci_resource_len(), i.e. the 'size', was 0 the ioremap would fail
so this function would never be called. So the first BUG_ON() can
never occur.

The 'order' returned by ilog2() will always be > 0 so the second
BUG_ON() will also never occur.

Remove the unnecessary BUG_ON() checks and tidy up the function.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>