keys: Remove outdated __user annotations

When the semantics of the ->read() handlers were changed such that "buffer"
is a kernel pointer, some __user annotations survived.
Since they're wrong now, get rid of them.

Fixes: d3ec10aa95 ("KEYS: Don't write out to userspace while holding key semaphore")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Ben Boeckel <mathstuf@gmail.com>

security/keys/keyring.c

@@ -452,7 +452,7 @@ static void keyring_describe(const struct key *keyring, struct seq_file *m)
 struct keyring_read_iterator_context {
 	size_t			buflen;
 	size_t			count;
-	key_serial_t __user	*buffer;
+	key_serial_t		*buffer;
 };
 
 static int keyring_read_iterator(const void *object, void *data)
@@ -479,7 +479,7 @@ static int keyring_read_iterator(const void *object, void *data)
  * times.
  */
 static long keyring_read(const struct key *keyring,
-			 char __user *buffer, size_t buflen)
+			 char *buffer, size_t buflen)
 {
 	struct keyring_read_iterator_context ctx;
 	long ret;
@@ -491,7 +491,7 @@ static long keyring_read(const struct key *keyring,
 
 	/* Copy as many key IDs as fit into the buffer */
 	if (buffer && buflen) {
-		ctx.buffer = (key_serial_t __user *)buffer;
+		ctx.buffer = (key_serial_t *)buffer;
 		ctx.buflen = buflen;
 		ctx.count = 0;
 		ret = assoc_array_iterate(&keyring->keys,