cpu/cc2538/periph/i2c: Made cppcheck happy
cpu/cc2538/periph/i2c: Made cppcheck happy

RIOT-OS/RIOT,kYc0o/RIOT,mtausig/RIOT,kYc0o/RIOT,ant9000/RIOT,mtausig/RIOT,authmillenon/RIOT,aeneby/RIOT,kaspar030/RIOT,authmillenon/RIOT,ant9000/RIOT,basilfx/RIOT,OTAkeys/RIOT,jasonatran/RIOT,basilfx/RIOT,aeneby/RIOT,authmillenon/RIOT,RIOT-OS/RIOT,yogo1212/RIOT,mtausig/RIOT,miri64/RIOT,yogo1212/RIOT,josephnoir/RIOT,kaspar030/RIOT,mtausig/RIOT,toonst/RIOT,toonst/RIOT,basilfx/RIOT,authmillenon/RIOT,OTAkeys/RIOT,OlegHahm/RIOT,basilfx/RIOT,toonst/RIOT,kaspar030/RIOT,jasonatran/RIOT,aeneby/RIOT,smlng/RIOT,authmillenon/RIOT,yogo1212/RIOT,yogo1212/RIOT,authmillenon/RIOT,yogo1212/RIOT,aeneby/RIOT,basilfx/RIOT,josephnoir/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,OlegHahm/RIOT,x3ro/RIOT,yogo1212/RIOT,toonst/RIOT,OTAkeys/RIOT,kYc0o/RIOT,smlng/RIOT,kYc0o/RIOT,OTAkeys/RIOT,x3ro/RIOT,kaspar030/RIOT,jasonatran/RIOT,smlng/RIOT,miri64/RIOT,aeneby/RIOT,josephnoir/RIOT,smlng/RIOT,jasonatran/RIOT,OlegHahm/RIOT,OTAkeys/RIOT,RIOT-OS/RIOT,toonst/RIOT,x3ro/RIOT,x3ro/RIOT,OlegHahm/RIOT,kaspar030/RIOT,x3ro/RIOT,kYc0o/RIOT,josephnoir/RIOT,OlegHahm/RIOT,ant9000/RIOT,RIOT-OS/RIOT,josephnoir/RIOT,miri64/RIOT,ant9000/RIOT,ant9000/RIOT,miri64/RIOT,smlng/RIOT,mtausig/RIOT,miri64/RIOT