lms: Return error on device read timeout

If LImeSDR device is unplugged or its fw crashes during operation,
reading from the device will fail and will first receive short reads and
finally 0 byte reads. Let's quickly notify these events to upper layers
instead of trying to process the buffer and checking timestamps for
something we know it's already not useful.

Related: OS#3340
Change-Id: Ib1af8cdd6cdadf581b039882add4049eea45a0f7
1 file changed