sys/irq_handler: fix typos
sys/irq_handler: fix typos

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