Undo part of 2.59: 't' case of convertsimple() should not use convertbuffer().
Undo part of 2.59: 't' case of convertsimple() should not use convertbuffer().

convertbuffer() uses the buffer interface's getreadbuffer(), but 't'
should use getcharbuffer().

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator