Fix various state_mutex leaks.  The worst one was introduced by the
interrutible state_mutex conversion but there've been a few before
too.  Notably spufs_wait now returns without the state_mutex held
when returning an error, which actually cleans up some code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NLuke Browning <lukebrowning@us.ibm.com>
Signed-off-by: NJeremy Kerr <jk@ozlabs.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>