cpu/esp: avoid reentrance of esp_now_recv_cb
cpu/esp: avoid reentrance of esp_now_recv_cb

Although it should not be possible to reenter the function esp_now_recv_cb, this is avoided by an additional boolean variable. It can not be realized by mutex because it would reenter from same thread context.  If macro NDEBUG is not defined, an assertion is used.
mtausig/RIOT,RIOT-OS/RIOT,smlng/RIOT,A-Paul/RIOT,lazytech-org/RIOT,josephnoir/RIOT,OlegHahm/RIOT,kaspar030/RIOT,rfuentess/RIOT,RIOT-OS/RIOT,kaspar030/RIOT,kYc0o/RIOT,cladmi/RIOT,OTAkeys/RIOT,miri64/RIOT,yogo1212/RIOT,toonst/RIOT,kaspar030/RIOT,BytesGalore/RIOT,smlng/RIOT,toonst/RIOT,authmillenon/RIOT,mtausig/RIOT,A-Paul/RIOT,authmillenon/RIOT,authmillenon/RIOT,mtausig/RIOT,josephnoir/RIOT,RIOT-OS/RIOT,cladmi/RIOT,lazytech-org/RIOT,OlegHahm/RIOT,yogo1212/RIOT,cladmi/RIOT,rfuentess/RIOT,mfrey/RIOT,rfuentess/RIOT,lazytech-org/RIOT,josephnoir/RIOT,kYc0o/RIOT,x3ro/RIOT,basilfx/RIOT,toonst/RIOT,kYc0o/RIOT,basilfx/RIOT,lazytech-org/RIOT,OlegHahm/RIOT,ant9000/RIOT,mtausig/RIOT,BytesGalore/RIOT,OTAkeys/RIOT,A-Paul/RIOT,x3ro/RIOT,jasonatran/RIOT,x3ro/RIOT,aeneby/RIOT,RIOT-OS/RIOT,yogo1212/RIOT,mfrey/RIOT,BytesGalore/RIOT,josephnoir/RIOT,mtausig/RIOT,rfuentess/RIOT,A-Paul/RIOT,OTAkeys/RIOT,x3ro/RIOT,authmillenon/RIOT,ant9000/RIOT,kaspar030/RIOT,mfrey/RIOT,ant9000/RIOT,smlng/RIOT,OTAkeys/RIOT,yogo1212/RIOT,kYc0o/RIOT,cladmi/RIOT,A-Paul/RIOT,BytesGalore/RIOT,mfrey/RIOT,smlng/RIOT,aeneby/RIOT,toonst/RIOT,authmillenon/RIOT,basilfx/RIOT,josephnoir/RIOT,jasonatran/RIOT,OlegHahm/RIOT,yogo1212/RIOT,OlegHahm/RIOT,miri64/RIOT,authmillenon/RIOT,mfrey/RIOT,basilfx/RIOT,basilfx/RIOT,aeneby/RIOT,miri64/RIOT,OTAkeys/RIOT,lazytech-org/RIOT,aeneby/RIOT,ant9000/RIOT,miri64/RIOT,x3ro/RIOT,smlng/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,kaspar030/RIOT,BytesGalore/RIOT,kYc0o/RIOT,miri64/RIOT,jasonatran/RIOT,yogo1212/RIOT,rfuentess/RIOT,cladmi/RIOT,toonst/RIOT,ant9000/RIOT,jasonatran/RIOT,aeneby/RIOT