Revert "vfs: do get_write_access() on upper layer of overlayfs"

This reverts commit 4d0c5ba2ff.

We now get write access on both overlay and underlying layers so this patch
is no longer needed for correct operation.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

fs/locks.c

@@ -1654,8 +1654,7 @@ check_conflicting_open(const struct dentry *dentry, const long arg, int flags)
 	if (flags & FL_LAYOUT)
 		return 0;
 
-	if ((arg == F_RDLCK) &&
-	    (atomic_read(&d_real_inode(dentry)->i_writecount) > 0))
+	if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0))
 		return -EAGAIN;
 
 	if ((arg == F_WRLCK) && ((d_count(dentry) > 1) ||