dist/tests/if_lib: use '==' for string comparison
dist/tests/if_lib: use '==' for string comparison

Signed-off-by: Yegor Yefremov <379041fa42359f10443de1f461b1b247ec449fae@googlemail.com>

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