script: abort if unused arguments are given

script: abort if unused arguments are given

scripts uses either a free-standing "file" argument, or the value
passed as --log-out "file". Additional filenames are ignored.
They are also ignored if --log-in "file" is given, as it turns off
output logging by default (can still be overriden by adding --log-out).
Avoid surprises when passing multiple filenames by writing usage
message instead.

[kzak@redhat.com: - use errtryhelp() rather than usage()]

Signed-off-by: Chris Hofstaedtler <zeha@debian.org>
Reported-by: наб <nabijaczleweli@nabijaczleweli.xyz>
Bug-Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1016193
Signed-off-by: Karel Zak <kzak@redhat.com>