Orangefs: set pos after generic_write_checks

if we are appending, generic_write_checks would have updated
pos to the end of the file...

Signed-off-by: Mike Marshall <hubcap@omnibond.com>
diff --git a/fs/orangefs/file.c b/fs/orangefs/file.c
index 78d296b..78a4696 100644
--- a/fs/orangefs/file.c
+++ b/fs/orangefs/file.c
@@ -430,7 +430,7 @@
 static ssize_t pvfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *iter)
 {
 	struct file *file = iocb->ki_filp;
-	loff_t pos = *(&iocb->ki_pos);
+	loff_t pos;
 	ssize_t rc;
 
 	BUG_ON(iocb->private);
@@ -461,6 +461,13 @@
 		goto out;
 	}
 
+	/*
+	 * if we are appending, generic_write_checks would have updated
+	 * pos to the end of the file, so we will wait till now to set
+	 * pos...
+	 */
+	pos = *(&iocb->ki_pos);
+
 	rc = do_readv_writev(PVFS_IO_WRITE,
 			     file,
 			     &pos,