fs: Turn __generic_write_end into a void function

The VFS-internal __generic_write_end helper always returns the value of
its @copied argument.  This can be confusing, and it isn't very useful
anyway, so turn __generic_write_end into a function returning void
instead.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
diff --git a/fs/internal.h b/fs/internal.h
index 6a8b716..530587f 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -44,7 +44,7 @@ static inline int __sync_blockdev(struct block_device *bdev, int wait)
 extern void guard_bio_eod(int rw, struct bio *bio);
 extern int __block_write_begin_int(struct page *page, loff_t pos, unsigned len,
 		get_block_t *get_block, struct iomap *iomap);
-int __generic_write_end(struct inode *inode, loff_t pos, unsigned copied,
+void __generic_write_end(struct inode *inode, loff_t pos, unsigned copied,
 		struct page *page);
 
 /*