[PARISC] Improve the error message when we get a clashing mod path

Improve the error message when we get a clashing mod path, and
actually display the IODC data and path for the conflicting device.

Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>