io_uring: remove sq/cq_off memset

We only have two reserved members we're not clearing, do so manually
instead. This is in preparation for using one of these members for
a new feature.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

io_uring/io_uring.c

@@ -3866,7 +3866,6 @@ static __cold int io_uring_create(unsigned entries, struct io_uring_params *p,
 	if (ret)
 		goto err;
 
-	memset(&p->sq_off, 0, sizeof(p->sq_off));
 	p->sq_off.head = offsetof(struct io_rings, sq.head);
 	p->sq_off.tail = offsetof(struct io_rings, sq.tail);
 	p->sq_off.ring_mask = offsetof(struct io_rings, sq_ring_mask);
@@ -3874,8 +3873,9 @@ static __cold int io_uring_create(unsigned entries, struct io_uring_params *p,
 	p->sq_off.flags = offsetof(struct io_rings, sq_flags);
 	p->sq_off.dropped = offsetof(struct io_rings, sq_dropped);
 	p->sq_off.array = (char *)ctx->sq_array - (char *)ctx->rings;
+	p->sq_off.resv1 = 0;
+	p->sq_off.resv2 = 0;
 
-	memset(&p->cq_off, 0, sizeof(p->cq_off));
 	p->cq_off.head = offsetof(struct io_rings, cq.head);
 	p->cq_off.tail = offsetof(struct io_rings, cq.tail);
 	p->cq_off.ring_mask = offsetof(struct io_rings, cq_ring_mask);
@@ -3883,6 +3883,8 @@ static __cold int io_uring_create(unsigned entries, struct io_uring_params *p,
 	p->cq_off.overflow = offsetof(struct io_rings, cq_overflow);
 	p->cq_off.cqes = offsetof(struct io_rings, cqes);
 	p->cq_off.flags = offsetof(struct io_rings, cq_flags);
+	p->cq_off.resv1 = 0;
+	p->cq_off.resv2 = 0;
 
 	p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP |
 			IORING_FEAT_SUBMIT_STABLE | IORING_FEAT_RW_CUR_POS |