sanitize vfs_fsync calling conventions

Now that the last user passing a NULL file pointer is gone we can remove
the redundant dentry argument and associated hacks inside vfs_fsynmc_range.

The next step will be removig the dentry argument from ->fsync, but given
the luck with the last round of method prototype changes I'd rather
defer this until after the main merge window.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index a90e83c..6120922 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -485,7 +485,7 @@
 				goto out;
 			}
 
-			ret = vfs_fsync(file, file->f_path.dentry, 0);
+			ret = vfs_fsync(file, 0);
 			if (unlikely(ret)) {
 				ret = -EIO;
 				goto out;
@@ -495,7 +495,7 @@
 		ret = lo_send(lo, bio, pos);
 
 		if (barrier && !ret) {
-			ret = vfs_fsync(file, file->f_path.dentry, 0);
+			ret = vfs_fsync(file, 0);
 			if (unlikely(ret))
 				ret = -EIO;
 		}