secril-client: close fds on I/O errors

if a kernel device returns an I/O error, it is better not to chew
the CPU resources retrying I/O operation on a not ready device.

Fixes periodical 100%-core load in audioserver after a voice call
completion.

Change-Id: I2b66ffd18c85823a11e50598a6b4e3c0245a0083