cpu/stm32_common/i2c: fix addr nack and flags
cpu/stm32_common/i2c: fix addr nack and flags

kYc0o/RIOT,biboc/RIOT,kaspar030/RIOT,avmelnikoff/RIOT,toonst/RIOT,RIOT-OS/RIOT,authmillenon/RIOT,OlegHahm/RIOT,josephnoir/RIOT,smlng/RIOT,miri64/RIOT,rfuentess/RIOT,mtausig/RIOT,mfrey/RIOT,gebart/RIOT,gebart/RIOT,basilfx/RIOT,ant9000/RIOT,josephnoir/RIOT,OlegHahm/RIOT,mtausig/RIOT,miri64/RIOT,kYc0o/RIOT,mfrey/RIOT,biboc/RIOT,authmillenon/RIOT,RIOT-OS/RIOT,BytesGalore/RIOT,smlng/RIOT,miri64/RIOT,aeneby/RIOT,kaspar030/RIOT,yogo1212/RIOT,kYc0o/RIOT,kYc0o/RIOT,kaspar030/RIOT,kYc0o/RIOT,ant9000/RIOT,lazytech-org/RIOT,aeneby/RIOT,jasonatran/RIOT,rfuentess/RIOT,basilfx/RIOT,cladmi/RIOT,OTAkeys/RIOT,ant9000/RIOT,toonst/RIOT,jasonatran/RIOT,x3ro/RIOT,A-Paul/RIOT,jasonatran/RIOT,BytesGalore/RIOT,aeneby/RIOT,miri64/RIOT,yogo1212/RIOT,mfrey/RIOT,lazytech-org/RIOT,rfuentess/RIOT,biboc/RIOT,authmillenon/RIOT,kbumsik/RIOT,kaspar030/RIOT,aeneby/RIOT,basilfx/RIOT,x3ro/RIOT,A-Paul/RIOT,cladmi/RIOT,jasonatran/RIOT,gebart/RIOT,lazytech-org/RIOT,rfuentess/RIOT,OTAkeys/RIOT,cladmi/RIOT,mtausig/RIOT,josephnoir/RIOT,gebart/RIOT,OTAkeys/RIOT,basilfx/RIOT,x3ro/RIOT,authmillenon/RIOT,miri64/RIOT,kaspar030/RIOT,A-Paul/RIOT,avmelnikoff/RIOT,josephnoir/RIOT,BytesGalore/RIOT,smlng/RIOT,yogo1212/RIOT,mtausig/RIOT,A-Paul/RIOT,kbumsik/RIOT,avmelnikoff/RIOT,jasonatran/RIOT,yogo1212/RIOT,OlegHahm/RIOT,cladmi/RIOT,biboc/RIOT,authmillenon/RIOT,BytesGalore/RIOT,mfrey/RIOT,josephnoir/RIOT,toonst/RIOT,RIOT-OS/RIOT,ant9000/RIOT,x3ro/RIOT,OTAkeys/RIOT,aeneby/RIOT,kbumsik/RIOT,cladmi/RIOT,x3ro/RIOT,OlegHahm/RIOT,kbumsik/RIOT,smlng/RIOT,yogo1212/RIOT,lazytech-org/RIOT,authmillenon/RIOT,toonst/RIOT,yogo1212/RIOT,avmelnikoff/RIOT,OTAkeys/RIOT,basilfx/RIOT,biboc/RIOT,rfuentess/RIOT,A-Paul/RIOT,OlegHahm/RIOT,kbumsik/RIOT,RIOT-OS/RIOT,avmelnikoff/RIOT,RIOT-OS/RIOT,BytesGalore/RIOT,gebart/RIOT,mfrey/RIOT,lazytech-org/RIOT,smlng/RIOT,toonst/RIOT,mtausig/RIOT,ant9000/RIOT