gnrc_sock_udp: fix possibly dereferenced NULL pointer (#6203)
gnrc_sock_udp: fix possibly dereferenced NULL pointer (#6203)


BytesGalore/RIOT,syin2/RIOT,LudwigOrtmann/RIOT,toonst/RIOT,OTAkeys/RIOT,kbumsik/RIOT,thomaseichinger/RIOT,thomaseichinger/RIOT,cladmi/RIOT,BytesGalore/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,ks156/RIOT,backenklee/RIOT,roberthartung/RIOT,gautric/RIOT,thomaseichinger/RIOT,gebart/RIOT,Hyungsin/RIOT-OS,toonst/RIOT,adrianghc/RIOT,basilfx/RIOT,plushvoxel/RIOT,lazytech-org/RIOT,LudwigOrtmann/RIOT,josephnoir/RIOT,plushvoxel/RIOT,cladmi/RIOT,dkm/RIOT,beurdouche/RIOT,jasonatran/RIOT,kYc0o/RIOT,Ell-i/RIOT,hamilton-mote/RIOT-OS,thomaseichinger/RIOT,LudwigKnuepfer/RIOT,adrianghc/RIOT,jbeyerstedt/RIOT-OTA-update,gautric/RIOT,kaspar030/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,BytesGalore/RIOT,mfrey/RIOT,dailab/RIOT,aeneby/RIOT,ant9000/RIOT,syin2/RIOT,yogo1212/RIOT,mtausig/RIOT,mfrey/RIOT,josephnoir/RIOT,neumodisch/RIOT,authmillenon/RIOT,x3ro/RIOT,backenklee/RIOT,x3ro/RIOT,jbeyerstedt/RIOT-OTA-update,miri64/RIOT,immesys/RiSyn,jfischer-phytec-iot/RIOT,aeneby/RIOT,rfuentess/RIOT,josephnoir/RIOT,TobiasFredersdorf/RIOT,jasonatran/RIOT,authmillenon/RIOT,mtausig/RIOT,BytesGalore/RIOT,OlegHahm/RIOT,smlng/RIOT,LudwigKnuepfer/RIOT,cladmi/RIOT,Ell-i/RIOT,OTAkeys/RIOT,Ell-i/RIOT,kb2ma/RIOT,cladmi/RIOT,jfischer-phytec-iot/RIOT,gebart/RIOT,LudwigOrtmann/RIOT,TobiasFredersdorf/RIOT,backenklee/RIOT,TobiasFredersdorf/RIOT,A-Paul/RIOT,RIOT-OS/RIOT,biboc/RIOT,miri64/RIOT,neumodisch/RIOT,immesys/RiSyn,LudwigOrtmann/RIOT,A-Paul/RIOT,Hyungsin/RIOT-OS,Ell-i/RIOT,plushvoxel/RIOT,dailab/RIOT,gautric/RIOT,OTAkeys/RIOT,neiljay/RIOT,neumodisch/RIOT,biboc/RIOT,ant9000/RIOT,jasonatran/RIOT,dkm/RIOT,rfuentess/RIOT,mfrey/RIOT,yogo1212/RIOT,hamilton-mote/RIOT-OS,kaspar030/RIOT,Josar/RIOT,ant9000/RIOT,thomaseichinger/RIOT,Hyungsin/RIOT-OS,jbeyerstedt/RIOT-OTA-update,adrianghc/RIOT,beurdouche/RIOT,kaspar030/RIOT,basilfx/RIOT,kaleb-himes/RIOT,kbumsik/RIOT,A-Paul/RIOT,OlegHahm/RIOT,neumodisch/RIOT,hamilton-mote/RIOT-OS,ks156/RIOT,ant9000/RIOT,x3ro/RIOT,ks156/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,neiljay/RIOT,biboc/RIOT,basilfx/RIOT,hamilton-mote/RIOT-OS,foss-for-synopsys-dwc-arc-processors/RIOT,syin2/RIOT,immesys/RiSyn,mfrey/RIOT,jfischer-phytec-iot/RIOT,adjih/RIOT,kb2ma/RIOT,kbumsik/RIOT,authmillenon/RIOT,smlng/RIOT,RIOT-OS/RIOT,OTAkeys/RIOT,kerneltask/RIOT,miri64/RIOT,neumodisch/RIOT,Josar/RIOT,Josar/RIOT,adrianghc/RIOT,gebart/RIOT,roberthartung/RIOT,ks156/RIOT,dailab/RIOT,avmelnikoff/RIOT,adjih/RIOT,kaspar030/RIOT,aeneby/RIOT,beurdouche/RIOT,kaspar030/RIOT,lazytech-org/RIOT,lazytech-org/RIOT,kYc0o/RIOT,yogo1212/RIOT,OlegHahm/RIOT,authmillenon/RIOT,katezilla/RIOT,kerneltask/RIOT,neiljay/RIOT,RIOT-OS/RIOT,kaleb-himes/RIOT,roberthartung/RIOT,kYc0o/RIOT,adrianghc/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,roberthartung/RIOT,Ell-i/RIOT,kerneltask/RIOT,kYc0o/RIOT,LudwigOrtmann/RIOT,kb2ma/RIOT,miri64/RIOT,neiljay/RIOT,TobiasFredersdorf/RIOT,aeneby/RIOT,katezilla/RIOT,LudwigKnuepfer/RIOT,yogo1212/RIOT,dkm/RIOT,A-Paul/RIOT,katezilla/RIOT,toonst/RIOT,avmelnikoff/RIOT,kaleb-himes/RIOT,Hyungsin/RIOT-OS,kbumsik/RIOT,jasonatran/RIOT,rfuentess/RIOT,gautric/RIOT,x3ro/RIOT,mtausig/RIOT,kbumsik/RIOT,mtausig/RIOT,hamilton-mote/RIOT-OS,ks156/RIOT,neiljay/RIOT,basilfx/RIOT,TobiasFredersdorf/RIOT,authmillenon/RIOT,kaleb-himes/RIOT,gebart/RIOT,yogo1212/RIOT,adjih/RIOT,OTAkeys/RIOT,plushvoxel/RIOT,mtausig/RIOT,smlng/RIOT,kaleb-himes/RIOT,BytesGalore/RIOT,kb2ma/RIOT,Josar/RIOT,jfischer-phytec-iot/RIOT,immesys/RiSyn,roberthartung/RIOT,avmelnikoff/RIOT,aeneby/RIOT,rfuentess/RIOT,lazytech-org/RIOT,adjih/RIOT,cladmi/RIOT,Hyungsin/RIOT-OS,avmelnikoff/RIOT,backenklee/RIOT,jbeyerstedt/RIOT-OTA-update,smlng/RIOT,plushvoxel/RIOT,avmelnikoff/RIOT,beurdouche/RIOT,adjih/RIOT,LudwigKnuepfer/RIOT,katezilla/RIOT,RIOT-OS/RIOT,basilfx/RIOT,dkm/RIOT,biboc/RIOT,beurdouche/RIOT,immesys/RiSyn,mfrey/RIOT,LudwigOrtmann/RIOT,Josar/RIOT,josephnoir/RIOT,A-Paul/RIOT,gautric/RIOT,immesys/RiSyn,smlng/RIOT,syin2/RIOT,dailab/RIOT,OlegHahm/RIOT,RIOT-OS/RIOT,kb2ma/RIOT,miri64/RIOT,dkm/RIOT,biboc/RIOT,jasonatran/RIOT,toonst/RIOT,LudwigKnuepfer/RIOT,syin2/RIOT,neumodisch/RIOT,gebart/RIOT,jfischer-phytec-iot/RIOT,kerneltask/RIOT,jbeyerstedt/RIOT-OTA-update,toonst/RIOT,authmillenon/RIOT,backenklee/RIOT,kYc0o/RIOT,ant9000/RIOT,kerneltask/RIOT,katezilla/RIOT,lazytech-org/RIOT,rfuentess/RIOT,dailab/RIOT,x3ro/RIOT,josephnoir/RIOT,OlegHahm/RIOT,yogo1212/RIOT