delay initialization of p, since alloca is only called later, move tmp_buff use downwards, since it is only used in printf128 mode

git-svn-id: https://svn.code.sf.net/p/mingw-w64/code@6352 4407c894-4637-0410-b4f5-ada5f102cad1
fix typo

git-svn-id: https://svn.code.sf.net/p/mingw-w64/code@6353 4407c894-4637-0410-b4f5-ada5f102cad1
merge from experimental

git-svn-id: https://svn.code.sf.net/p/mingw-w64/code@6354 4407c894-4637-0410-b4f5-ada5f102cad1