[bgpd] Fix infinite loop in community_str2com

[bgpd] Fix infinite loop in community_str2com

2006-03-30 Paul Jakma <paul.jakma@sun.com>

	* bgp_community.c: (community_gettoken) Unknown token should
	  return NULL, to give a strong indication to callers that
	  the token no longer can be parsed, otherwise callers looping
	  on this function may have a hard time ending their loop.
	  (community_str2com) While loop around community_gettoken appears
	  to have been coded thinking that break statement would break
	  from the while{}, hence it could never exit for unknown token
	  case. Fix it to do..while, so it can use the NULL result from
	  community_gettoken easily.