Convert libsmapinfo stringstreams to ostreams

This change converts all usages of stringstream in libsmapinfo to
ostream. This is done as a prerequisite change to refactoring showmap
functions into this library, since showmap print functions use ostream.

Test: Checked that librank and procrank still return the same output.
Bug: 229147699
Change-Id: I9255226070e4f4f45c8cbb2181a307cff5dfc4a2
2 files changed