beaglebone.c: check devpath only once in i2c_init_pre
beaglebone.c: check devpath only once in i2c_init_pre

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

stefan-andritoiu/mraa,sergev/mraa,KurtE/mraa,arfoll/mraa,ncrastanaren/mraa,malikabhi05/mraa,malikabhi05/mraa,Propanu/mraa,sergev/mraa,yongli3/mraa,Propanu/mraa,intel-iot-devkit/mraa,g-vidal/mraa,stefan-andritoiu/mraa,arfoll/mraa,arfoll/mraa,g-vidal/mraa,stefan-andritoiu/mraa,stefan-andritoiu/mraa,Propanu/mraa,Propanu/mraa,arfoll/mraa,intel-iot-devkit/mraa,alext-mkrs/mraa,alext-mkrs/mraa,yongli3/mraa,sergev/mraa,g-vidal/mraa,sergev/mraa,malikabhi05/mraa,g-vidal/mraa,KurtE/mraa,sergev/mraa,ncrastanaren/mraa,yongli3/mraa,ncrastanaren/mraa,malikabhi05/mraa,alext-mkrs/mraa,yongli3/mraa,Propanu/mraa,arfoll/mraa,intel-iot-devkit/mraa,intel-iot-devkit/mraa,yongli3/mraa,alext-mkrs/mraa,malikabhi05/mraa,alext-mkrs/mraa,intel-iot-devkit/mraa,ncrastanaren/mraa,KurtE/mraa,g-vidal/mraa,KurtE/mraa,stefan-andritoiu/mraa,ncrastanaren/mraa,KurtE/mraa