IB/hfi1: Use bool in process_ecn

The process_ecn intends to return a bool value. However it is doing
so incorrectly by ANDing the fecn mask. The fecn bit is bit 31. Bool is
not a native data type and is up to the compiler to implement how it
sees fit. It is conceivable that this upper bit gets washed out.

Fix by converting to a bool properly.

Cc: stable@vger.kernel.org
Fixes: Commit fd2b562edca6 ("IB/hfi1: Pull FECN/BECN processing to a common place")
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/hfi1/rc.c

@@ -1930,7 +1930,8 @@ void hfi1_rc_rcv(struct hfi1_packet *packet)
 	int diff;
 	struct ib_reth *reth;
 	unsigned long flags;
-	int ret, is_fecn = 0;
+	int ret;
+	bool is_fecn = false;
 	bool copy_last = false;
 	u32 rkey;