Allocate stringbuf_t objects using a single apr_palloc call.
Allocate stringbuf_t objects using a single apr_palloc call.

* subversion/libsvn_subr/svn_string.c
  (svn_stringbuf_create_ensure): model in symmetry to svn_string_ncreate

git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1103486 13f79535-47bb-0310-9956-ffa450edef68

wbond/subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion