[patch 10/10] s390: qeth bug fixes.

From: Frank Pavlic <pavlic@de.ibm.com>

qeth network driver related changes:
 - due to OSA hardware changes in TCP Segmentation Offload
   support we are able now to pack TSO packets too.
   This fits perfectly in design of qeth buffer handling and
   sending data respectively.
 - remove skb_realloc_headroom from the sending path since
   hard_header_len value provides enough headroom now.
 - device recovery behaviour improvement
 - bug fixed in Enhanced Device Driver Packing functionality
Signed-off-by: Frank Pavlic <pavlic@de.ibm.com>