staging: comedi: me_daq: cleanup ioremap of PCI bar 2

PCI bar 2 is the main i/o address for this driver. Currently the
pci_resource_len of the bar is stored in the private data but
it is never used.

Remove 'me_regbase_size' from the private data. Also, remove the
local variables used for the pci_resource_start and _len. Just
pass the values directly to the ioremap().

Remove the kernel noise when the ioremap fails.

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