common.h: Added destructor attribute for deinit
common.h: Added destructor attribute for deinit

Currently, mraa_init is called when loading libmraa.  This commit
adds similar functionality to call mraa_deinit when unloading
libmraa.  This is a nice-to-have since it makes identifying other
memory leaks easier.

Signed-off-by: Noel Eck <1e36ab6ededef40f3f16bdbc1b09eee72c5d08cf@intel.com>
Signed-off-by: Brendan Le Foll <3e0e8c4069934e8b47d99704927a85c66c0ceb33@intel.com>

Propanu/mraa,stefan-andritoiu/mraa,intel-iot-devkit/mraa,malikabhi05/mraa,KurtE/mraa,Propanu/mraa,yongli3/mraa,g-vidal/mraa,KurtE/mraa,intel-iot-devkit/mraa,arunlee77/mraa,stefan-andritoiu/mraa-gpio-chardev,stefan-andritoiu/mraa,yongli3/mraa,KurtE/mraa,arfoll/mraa,stefan-andritoiu/mraa,Jon-ICS/mraa,malikabhi05/mraa,Jon-ICS/mraa,yongli3/mraa,arfoll/mraa,ncrastanaren/mraa,stefan-andritoiu/mraa-gpio-chardev,Propanu/mraa,stefan-andritoiu/mraa,sergev/mraa,arunlee77/mraa,jontrulson/mraa,sergev/mraa,malikabhi05/mraa,arfoll/mraa,g-vidal/mraa,Jon-ICS/mraa,alext-mkrs/mraa,jontrulson/mraa,jontrulson/mraa,malikabhi05/mraa,alext-mkrs/mraa,arfoll/mraa,spitfire88/mraa,ncrastanaren/mraa,KurtE/mraa,yongli3/mraa,jontrulson/mraa,intel-iot-devkit/mraa,spitfire88/mraa,alext-mkrs/mraa,sergev/mraa,alext-mkrs/mraa,stefan-andritoiu/mraa-gpio-chardev,intel-iot-devkit/mraa,Propanu/mraa,KurtE/mraa,yongli3/mraa,ncrastanaren/mraa,stefan-andritoiu/mraa-gpio-chardev,arunlee77/mraa,stefan-andritoiu/mraa-gpio-chardev,stefan-andritoiu/mraa,arfoll/mraa,arunlee77/mraa,sergev/mraa,g-vidal/mraa,spitfire88/mraa,g-vidal/mraa,malikabhi05/mraa,g-vidal/mraa,intel-iot-devkit/mraa,spitfire88/mraa,jontrulson/mraa,sergev/mraa,ncrastanaren/mraa,Propanu/mraa,ncrastanaren/mraa,alext-mkrs/mraa