Follow up to r22457: cleanup and add extra comment.
Follow up to r22457: cleanup and add extra comment.

Suggested by: dlr

* subversion/libsvn_subr/path.c
  (svn_path_is_root): add comment explaining the need for this custom 
   implementation. Fix some whitespaces to match our coding guidelines.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion