selftests/bpf: Cleanup comments in test_maps

Make comments inside the test_map_rdonly and test_map_wronly tests
consistent with logic.

Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200527185700.14658-4-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/test_maps.c

@@ -1394,11 +1394,11 @@ static void test_map_rdonly(void)
 
 	key = 1;
 	value = 1234;
-	/* Insert key=1 element. */
+	/* Try to insert key=1 element. */
 	assert(bpf_map_update_elem(fd, &key, &value, BPF_ANY) == -1 &&
 	       errno == EPERM);
 
-	/* Check that key=2 is not found. */
+	/* Check that key=1 is not found. */
 	assert(bpf_map_lookup_elem(fd, &key, &value) == -1 && errno == ENOENT);
 	assert(bpf_map_get_next_key(fd, &key, &value) == -1 && errno == ENOENT);
 
@@ -1422,7 +1422,7 @@ static void test_map_wronly(void)
 	/* Insert key=1 element. */
 	assert(bpf_map_update_elem(fd, &key, &value, BPF_ANY) == 0);
 
-	/* Check that key=2 is not found. */
+	/* Check that reading elements and keys from the map is not allowed. */
 	assert(bpf_map_lookup_elem(fd, &key, &value) == -1 && errno == EPERM);
 	assert(bpf_map_get_next_key(fd, &key, &value) == -1 && errno == EPERM);