git-svn: remove check_path calls before calling do_update

git-svn: remove check_path calls before calling do_update

These checks were needed before git-svn got smarter about
match_paths() and using path information returned by get_log().
We also have extra checking against fetching revisions
out-of-order these days; so we don't have to worry about that as
much.  We also check for tree deletions in match_paths() and
skip those as well.

Signed-off-by: Eric Wong <normalperson@yhbt.net>