sys/saul_reg: fixed return val doc for write func
sys/saul_reg: fixed return val doc for write func

BytesGalore/RIOT,syin2/RIOT,avmelnikoff/RIOT,aeneby/RIOT,beurdouche/RIOT,josephnoir/RIOT,basilfx/RIOT,authmillenon/RIOT,A-Paul/RIOT,x3ro/RIOT,plushvoxel/RIOT,dailab/RIOT,LudwigOrtmann/RIOT,kaleb-himes/RIOT,immesys/RiSyn,OTAkeys/RIOT,lazytech-org/RIOT,A-Paul/RIOT,aeneby/RIOT,beurdouche/RIOT,Hyungsin/RIOT-OS,neiljay/RIOT,Ell-i/RIOT,smlng/RIOT,dailab/RIOT,cladmi/RIOT,kerneltask/RIOT,neumodisch/RIOT,RIOT-OS/RIOT,ant9000/RIOT,roberthartung/RIOT,neiljay/RIOT,miri64/RIOT,BytesGalore/RIOT,adrianghc/RIOT,miri64/RIOT,A-Paul/RIOT,gebart/RIOT,RIOT-OS/RIOT,BytesGalore/RIOT,mtausig/RIOT,ks156/RIOT,x3ro/RIOT,kerneltask/RIOT,adjih/RIOT,A-Paul/RIOT,gautric/RIOT,Ell-i/RIOT,authmillenon/RIOT,josephnoir/RIOT,A-Paul/RIOT,smlng/RIOT,immesys/RiSyn,LudwigOrtmann/RIOT,rfuentess/RIOT,roberthartung/RIOT,gebart/RIOT,basilfx/RIOT,yogo1212/RIOT,yogo1212/RIOT,LudwigKnuepfer/RIOT,jfischer-phytec-iot/RIOT,LudwigKnuepfer/RIOT,miri64/RIOT,rfuentess/RIOT,dailab/RIOT,mtausig/RIOT,biboc/RIOT,hamilton-mote/RIOT-OS,hamilton-mote/RIOT-OS,foss-for-synopsys-dwc-arc-processors/RIOT,mfrey/RIOT,mfrey/RIOT,kaspar030/RIOT,x3ro/RIOT,kaspar030/RIOT,neumodisch/RIOT,cladmi/RIOT,toonst/RIOT,avmelnikoff/RIOT,Hyungsin/RIOT-OS,mfrey/RIOT,mfrey/RIOT,thomaseichinger/RIOT,yogo1212/RIOT,Josar/RIOT,syin2/RIOT,authmillenon/RIOT,authmillenon/RIOT,hamilton-mote/RIOT-OS,kaleb-himes/RIOT,syin2/RIOT,kaspar030/RIOT,adrianghc/RIOT,aeneby/RIOT,rfuentess/RIOT,lazytech-org/RIOT,roberthartung/RIOT,BytesGalore/RIOT,kbumsik/RIOT,gautric/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,kYc0o/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,jfischer-phytec-iot/RIOT,kbumsik/RIOT,LudwigOrtmann/RIOT,immesys/RiSyn,LudwigKnuepfer/RIOT,smlng/RIOT,immesys/RiSyn,dkm/RIOT,jfischer-phytec-iot/RIOT,Hyungsin/RIOT-OS,authmillenon/RIOT,toonst/RIOT,gautric/RIOT,hamilton-mote/RIOT-OS,kYc0o/RIOT,adrianghc/RIOT,josephnoir/RIOT,LudwigKnuepfer/RIOT,toonst/RIOT,jasonatran/RIOT,rfuentess/RIOT,jasonatran/RIOT,OlegHahm/RIOT,plushvoxel/RIOT,ks156/RIOT,plushvoxel/RIOT,plushvoxel/RIOT,thomaseichinger/RIOT,cladmi/RIOT,josephnoir/RIOT,kerneltask/RIOT,avmelnikoff/RIOT,neumodisch/RIOT,ant9000/RIOT,dkm/RIOT,LudwigOrtmann/RIOT,kYc0o/RIOT,kaspar030/RIOT,smlng/RIOT,cladmi/RIOT,dailab/RIOT,miri64/RIOT,x3ro/RIOT,aeneby/RIOT,miri64/RIOT,hamilton-mote/RIOT-OS,yogo1212/RIOT,neiljay/RIOT,authmillenon/RIOT,thomaseichinger/RIOT,jasonatran/RIOT,avmelnikoff/RIOT,smlng/RIOT,cladmi/RIOT,immesys/RiSyn,lazytech-org/RIOT,roberthartung/RIOT,neumodisch/RIOT,OlegHahm/RIOT,kYc0o/RIOT,OTAkeys/RIOT,Josar/RIOT,RIOT-OS/RIOT,adjih/RIOT,immesys/RiSyn,kaleb-himes/RIOT,kaspar030/RIOT,Hyungsin/RIOT-OS,kaleb-himes/RIOT,OlegHahm/RIOT,Ell-i/RIOT,plushvoxel/RIOT,mfrey/RIOT,LudwigOrtmann/RIOT,toonst/RIOT,OlegHahm/RIOT,Ell-i/RIOT,thomaseichinger/RIOT,lazytech-org/RIOT,gebart/RIOT,rfuentess/RIOT,kbumsik/RIOT,dkm/RIOT,yogo1212/RIOT,adjih/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,ks156/RIOT,josephnoir/RIOT,syin2/RIOT,jfischer-phytec-iot/RIOT,ant9000/RIOT,jasonatran/RIOT,ant9000/RIOT,beurdouche/RIOT,beurdouche/RIOT,Josar/RIOT,jasonatran/RIOT,LudwigOrtmann/RIOT,neiljay/RIOT,OlegHahm/RIOT,toonst/RIOT,yogo1212/RIOT,OTAkeys/RIOT,syin2/RIOT,kYc0o/RIOT,avmelnikoff/RIOT,ant9000/RIOT,gebart/RIOT,lazytech-org/RIOT,gautric/RIOT,OTAkeys/RIOT,kbumsik/RIOT,basilfx/RIOT,biboc/RIOT,RIOT-OS/RIOT,kbumsik/RIOT,mtausig/RIOT,dkm/RIOT,adrianghc/RIOT,dailab/RIOT,roberthartung/RIOT,beurdouche/RIOT,kaleb-himes/RIOT,OTAkeys/RIOT,dkm/RIOT,neumodisch/RIOT,biboc/RIOT,biboc/RIOT,ks156/RIOT,kerneltask/RIOT,aeneby/RIOT,basilfx/RIOT,basilfx/RIOT,gautric/RIOT,ks156/RIOT,adjih/RIOT,neumodisch/RIOT,gebart/RIOT,Hyungsin/RIOT-OS,mtausig/RIOT,Josar/RIOT,mtausig/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,kerneltask/RIOT,Ell-i/RIOT,RIOT-OS/RIOT,x3ro/RIOT,biboc/RIOT,LudwigKnuepfer/RIOT,adrianghc/RIOT,BytesGalore/RIOT,thomaseichinger/RIOT,adjih/RIOT,Josar/RIOT,neiljay/RIOT,jfischer-phytec-iot/RIOT