xsk: Simplify xp_aligned_validate_desc implementation

Perform the chunk boundary check like the page boundary check in
xp_desc_crosses_non_contig_pg(). This simplifies the implementation and
reduces the number of branches.
Signed-off-by: Kal Conley <kal.conley@dectris.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20230410121841.643254-1-kal.conley@dectris.com

net/xdp/xsk_queue.h

@@ -133,16 +133,12 @@ static inline bool xskq_cons_read_addr_unchecked(struct xsk_queue *q, u64 *addr)
 static inline bool xp_aligned_validate_desc(struct xsk_buff_pool *pool,
 					    struct xdp_desc *desc)
 {
-	u64 chunk, chunk_end;
+	u64 offset = desc->addr & (pool->chunk_size - 1);
 
-	chunk = xp_aligned_extract_addr(pool, desc->addr);
-	if (likely(desc->len)) {
-		chunk_end = xp_aligned_extract_addr(pool, desc->addr + desc->len - 1);
-		if (chunk != chunk_end)
-			return false;
-	}
+	if (offset + desc->len > pool->chunk_size)
+		return false;
 
-	if (chunk >= pool->addrs_cnt)
+	if (desc->addr >= pool->addrs_cnt)
 		return false;
 
 	if (desc->options)