spufs_rmdir tries to acquire the spufs root
i_mutex, which is already held by spufs_create_thread.

This was tracked as Bug #H9512.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NArnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>