Correct a bug introduced in sys_pipe.c:1.179: in pipe_ioctl(), release the pipe mutex before calling fsetown(), as fsetown() may block.  The sigio code protects the pipe sigio data using its own mutex, and the pipe reference count held by the caller will prevent the pipe from being prematurely garbage-collected.
Correct a bug introduced in sys_pipe.c:1.179: in pipe_ioctl(),
release the pipe mutex before calling fsetown(), as fsetown()
may block.  The sigio code protects the pipe sigio data using
its own mutex, and the pipe reference count held by the caller
will prevent the pipe from being prematurely garbage-collected.

Discovered by:	imp

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase