selftests/xsk: Put MAP_HUGE_2MB in correct argument

Put the flag MAP_HUGE_2MB in the correct flags argument instead of the
wrong offset argument.

Fixes: 2ddade3229 ("selftests/xsk: Fix munmap for hugepage allocated umem")
Reported-by: Kal Cutter Conley <kal.conley@dectris.com>
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230421062208.3772-1-magnus.karlsson@gmail.com

tools/testing/selftests/bpf/xskxceiver.c

@@ -1287,19 +1287,16 @@ static void thread_common_ops(struct test_spec *test, struct ifobject *ifobject)
 	u64 umem_sz = ifobject->umem->num_frames * ifobject->umem->frame_size;
 	int mmap_flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE;
 	LIBBPF_OPTS(bpf_xdp_query_opts, opts);
-	off_t mmap_offset = 0;
 	void *bufs;
 	int ret;
 
-	if (ifobject->umem->unaligned_mode) {
-		mmap_flags |= MAP_HUGETLB;
-		mmap_offset = MAP_HUGE_2MB;
-	}
+	if (ifobject->umem->unaligned_mode)
+		mmap_flags |= MAP_HUGETLB | MAP_HUGE_2MB;
 
 	if (ifobject->shared_umem)
 		umem_sz *= 2;
 
-	bufs = mmap(NULL, umem_sz, PROT_READ | PROT_WRITE, mmap_flags, -1, mmap_offset);
+	bufs = mmap(NULL, umem_sz, PROT_READ | PROT_WRITE, mmap_flags, -1, 0);
 	if (bufs == MAP_FAILED)
 		exit_with_error(errno);
 
@@ -1633,7 +1630,7 @@ static bool hugepages_present(struct ifobject *ifobject)
 	void *bufs;
 
 	bufs = mmap(NULL, mmap_sz, PROT_READ | PROT_WRITE,
-		    MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, -1, MAP_HUGE_2MB);
+		    MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB | MAP_HUGE_2MB, -1, 0);
 	if (bufs == MAP_FAILED)
 		return false;