hecking in init and deinit functions

Improve the error checking in the IR init and deinit functions.
Based on Darren Salt's dvb-ir patchset.

Signed-off-by: David Hardeman <david@hardeman.nu>
Signed-off-by: Andrew de Quincey <adq_dvb@lidskialf.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
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