xprtrdma: Squelch a sparse warning

mainline inclusion
from mainline-4.20-rc1
commit 470443e0b379b070305629f911cc09562bdf324f
category: bugfix
bugzilla: 5551
CVE: NA

---------------------------

linux/include/trace/events/rpcrdma.h:501:1: warning: expression using sizeof bool
linux/include/trace/events/rpcrdma.h:501:1: warning: odd constant _Bool cast (ffffffffffffffff becomes 1)

Fixes: ab03eff5 ("xprtrdma: Add trace points in RPC Call ... ")
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NJason Yan <yanaijie@huawei.com>
Reviewed-by: Nzhengbin <zhengbin13@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

include/trace/events/rpcrdma.h

@@ -509,7 +509,7 @@ TRACE_EVENT(xprtrdma_post_send,
 	TP_STRUCT__entry(
 		__field(const void *, req)
 		__field(int, num_sge)
-		__field(bool, signaled)
+		__field(int, signaled)
 		__field(int, status)
 	),