ddd84d08 "Convert
SV_DECL_PTRARR_SORT_DEL(_SwRedlineTbl) to o3tl::sorted_vector" had introduced
size and operator[] operating on underlying vector's size_type, but had left the
other functions at sal_uInt16.  Keep everything at sal_uInt16 for now until
fixing everything to use that underlying vector size_type instead.

Change-Id: I92570dcb8ab5fa88b52e2b24899b833829693a88