staging: comedi: s626: cleanup ioremap()

The local variable 'resourceStart' is only used in the ioremap()
to hold the PCI bar 0 base address. Just use the pci_resource_start()
directly in the ioremap().

Also, instead of assuming the resource size for the ioremap, use
pci_resource_len() to get the actual size.

Remove the kernel noise when the ioremap fails and change the error
code from -ENODEV to -ENOMEM.

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>