S2io: sw bug fixes

Hi,
Attached is the second patch in this submission. It contains the following software bug fixes.

1. In free_rx_buffers clearing out RxDs not owned by Xena.

2. In alarm_intr_handler, when a serr error occurs, schedule a task to reset the card rather than stopping Tx queue.

3. In s2io_close freeing IRQ before calling s2io_reset also added a new call to flush queued tasks. This is not done if the s2io_close itself is called from a queued task like s2io_restart_nic.

4. read_eeprom function has been changed such that data to be returned is sent as an input argument and the return value represents a pass/fail. The previous implementation as Randy had pointed out was error prone as on failure it returned -1 which can be interpreted as all ff's, so any data area which contained ff's in the eeprom was likely to be treated as an error.

5. Added a flag "task_flag" to track if the call to s2io_close is coming from the s2io_restart_nic function or from the ifconfig <I/F> down called by user.

6. Moved register_netdev call from just after setting entry points to the end of the s2io_init_nic function.

7. In s2io.h field added a new member into the s2io_nic structure called "task_flag".

Thanks,
Ravi