net: sun: fix missing release regions in cas_init_one().

In cas_init_one(), "pdev" is requested by "pci_request_regions", but it
was not released after a call of the function “pci_write_config_byte”
failed. Thus replace the jump target “err_write_cacheline” by
"err_out_free_res".

Fixes: 1f26dac3 ("[NET]: Add Sun Cassini driver.")
Signed-off-by: Qiushi Wu <wu000273@umn.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>