cxgb4: fix boolreturn.cocci warnings

drivers/net/ethernet/chelsio/cxgb4/cxgb4_fcoe.c:49:9-10: WARNING: return of 0/1 in function 'cxgb_fcoe_sof_eof_supported' with return type bool

 Return statements in functions returning bool should use
 true/false instead of 1/0.
Generated by: scripts/coccinelle/misc/boolreturn.cocci

CC: Varun Prakash <varun@chelsio.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>