IIOD: Handle client disconnections in readfd_io() / writefd_io()
IIOD: Handle client disconnections in readfd_io() / writefd_io()

Now, in the (unlikely) event that the client disconnects right after
sending its READBUF or WRITEBUF command, IIOD won't poll the socket
indefinitely while locking mutexes, preventing other clients from
connecting.

Signed-off-by: Paul Cercueil <73d292422978d45c9eeef455bb1b24a0db453722@analog.com>

analogdevicesinc/libiio,analogdevicesinc/libiio,analogdevicesinc/libiio,analogdevicesinc/libiio