This is a combination of 2 commits.

aio: mraa_aio_read (v1.0.0) can now return -1, treat that in sensors using it

Adds alot of exceptions if the aio read goes wrong

Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
Signed-off-by: Noel Eck <noel.eck@intel.com>

src/guvas12d/guvas12d.cxx

@@ -54,6 +54,7 @@ float GUVAS12D::value(float aref, unsigned int samples)
   for (int i=0; i<samples; i++)
     {
       val = mraa_aio_read(m_aio);
+      if (val == -1) return -1;
       sum += val;
       usleep(2000);
     }