pcnet32: add missing check for pci_dma_mapping_error

The pci_map_single calls never checked for error. Add error checking
as requested by someone last year.  Tested on 79c972.

Signed-off-by: Don Fry <pcnet32@frontier.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed