Revert "vfs: Allow userns root to call mknod on owned filesystems."

This causes issues for unprivileged containers. This should be
re-applied once the container daemon has been updated to be compatible.

This reverts commit 55956b59df336f6738da916dbb520b6e37df9fbd.

Change-Id: Ib89b0748257ecc0305034425514abd9d83b27933

fs/namei.c

diff --git a/fs/namei.c b/fs/namei.c
index 734cef5..389e48e 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3711,8 +3711,7 @@ int vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
 	if (error)
 		return error;
 
-	if ((S_ISCHR(mode) || S_ISBLK(mode)) &&
-	    !ns_capable(dentry->d_sb->s_user_ns, CAP_MKNOD))
+	if ((S_ISCHR(mode) || S_ISBLK(mode)) && !capable(CAP_MKNOD))
 		return -EPERM;
 
 	if (!dir->i_op->mknod)