[PATCH][next] IB/hfi1: Avoid -Wflex-array-member-not-at-end warning

["Gustavo A. R. Silva" <gustavoars@kernel.org>]

-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.

Move the conflicting declaration to the end of the structure. Notice
that `struct opa_mad_notice_attr` is a flexible structure --a structure
that contains a flexible-array member.

Fix the following warning:

drivers/infiniband/hw/hfi1/mad.c:23:36: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/infiniband/hw/hfi1/mad.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/hfi1/mad.c b/drivers/infiniband/hw/hfi1/mad.c
index b39f63ce6dfc..3f11a90819d1 100644
--- a/drivers/infiniband/hw/hfi1/mad.c
+++ b/drivers/infiniband/hw/hfi1/mad.c
@@ -20,12 +20,14 @@
 
 struct trap_node {
 	struct list_head list;
-	struct opa_mad_notice_attr data;
 	__be64 tid;
 	int len;
 	u32 retry;
 	u8 in_use;
 	u8 repress;
+
+	/* Must be last --ends in a flexible-array member. */
+	struct opa_mad_notice_attr data;
 };
 
 static int smp_length_check(u32 data_size, u32 request_len)
-- 
2.43.0