Fnic: Memcopy only mimumum of data or trace buffer

In case of receive path, we do not have eth header or fcoe header available
when we take a trace so we fill the fc trace buffer with 0xff for both
values. We copy only mimimum of received data or trace buffer size -
fc header - eth and fcoe header

- Increment fnic version from 1.6.0.12 to 1.6.0.13

Signed-off-by: Hiral Shah <hishah@cisco.com>
Signed-off-by: Sesidhar Baddela <sebaddel@cisco.com>
Signed-off-by: Anil Chintalapati <achintal@cisco.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>