do_shmem_file_read(): call file_read_actor() directly

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

mm/shmem.c

@@ -1462,7 +1462,7 @@ shmem_write_end(struct file *file, struct address_space *mapping,
 	return copied;
 }
 
-static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_t *desc, read_actor_t actor)
+static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_t *desc)
 {
 	struct inode *inode = file_inode(filp);
 	struct address_space *mapping = inode->i_mapping;
@@ -1550,7 +1550,7 @@ static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_
 		 * "pos" here (the actor routine has to update the user buffer
 		 * pointers and the remaining count).
 		 */
-		ret = actor(desc, page, offset, nr);
+		ret = file_read_actor(desc, page, offset, nr);
 		offset += ret;
 		index += offset >> PAGE_CACHE_SHIFT;
 		offset &= ~PAGE_CACHE_MASK;
@@ -1588,7 +1588,7 @@ static ssize_t shmem_file_aio_read(struct kiocb *iocb,
 		if (desc.count == 0)
 			continue;
 		desc.error = 0;
-		do_shmem_file_read(filp, ppos, &desc, file_read_actor);
+		do_shmem_file_read(filp, ppos, &desc);
 		retval += desc.written;
 		if (desc.error) {
 			retval = retval ?: desc.error;