Change VG_(readlink) and VG_(resolve_filename) to return pointer to
dynamically allocated string which will be overwritten with each 
invocation. Fix call sites.


git-svn-id: svn://svn.valgrind.org/valgrind/branches/BUF_REMOVAL@14210 a5019735-40e9-0310-863c-91ae7b9d1cf9