gnrc_tcp: fix return on closed state
gnrc_tcp: fix return on closed state

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