Although not fundamentally necessary to check return codes in these
spots, preventing the warnings will put new ones into focus.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Instead of calling rewind() and fgets() before every call to
scan_lines(), move them into scan_lines() itself.
This should also fix compat mode, as before the second call to
scan_lines() the first line was skipped unconditionally.
Signed-off-by: Phil Sutter <phil@nwl.cc>
