[nrf52480] Fix for buffer overrun in otPlatLog (#2384)
[nrf52480] Fix for buffer overrun in otPlatLog (#2384)

This commit addresses a misunderstanding of what the return value of `vsnprintf()` means.

This fixes issue #2382.
mszczodrak/openthread,pvanhorn/openthread,lanyuwen/openthread,bukepo/openthread,xiaom-GitHub/openthread,mszczodrak/openthread,chshu/openthread,lanyuwen/openthread,LeZhang2016/openthread,georgecpr/openthread,erja-gp/openthread,jwhui/openthread,turon/openthread,xiaom-GitHub/openthread,openthread/openthread,lanyuwen/openthread,chshu/openthread,xiaom-GitHub/openthread,bukepo/openthread,librasungirl/openthread,gandreello/openthread,xiaom-GitHub/openthread,srickardti/openthread,openthread/openthread,xiaom-GitHub/openthread,gandreello/openthread,pvanhorn/openthread,georgecpr/openthread,pvanhorn/openthread,LeZhang2016/openthread,erja-gp/openthread,abtink/openthread,abtink/openthread,georgecpr/openthread,jwhui/openthread,pvanhorn/openthread,lanyuwen/openthread,erja-gp/openthread,chshu/openthread,georgecpr/openthread,gandreello/openthread,pvanhorn/openthread,turon/openthread,gandreello/openthread,LeZhang2016/openthread,georgecpr/openthread,bukepo/openthread,chshu/openthread,pvanhorn/openthread,erja-gp/openthread,jwhui/openthread,abtink/openthread,georgecpr/openthread,openthread/openthread,abtink/openthread,mszczodrak/openthread,LeZhang2016/openthread,srickardti/openthread,chshu/openthread,erja-gp/openthread,LeZhang2016/openthread,mszczodrak/openthread,openthread/openthread,turon/openthread,turon/openthread,srickardti/openthread,jwhui/openthread,mszczodrak/openthread,bukepo/openthread,srickardti/openthread,mszczodrak/openthread,LeZhang2016/openthread,librasungirl/openthread,librasungirl/openthread,gandreello/openthread,lanyuwen/openthread,librasungirl/openthread,erja-gp/openthread,lanyuwen/openthread,gandreello/openthread,xiaom-GitHub/openthread,chshu/openthread