Previously, buffer descriptors containing only the frame check sequence
(FCS) were skipped and not added to the skb. However, the page reference
count was still incremented, leading to a memory leak.

Fixing this inside gfar_add_rx_frag() is difficult due to reserved
memory handling and page reuse. Instead, move the FCS handling to
gfar_process_frame() and trim off the FCS before passing the skb up the
networking stack.
Signed-off-by: Andy Spencer <aspencer@spacex.com>
Signed-off-by: Jim Gruen <jgruen@spacex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>