Fix NameError in scan.py and wrong return type in probe.py

scan.py: `logger` was used instead of `self.logger`, causing a NameError
when an unrecognized language code is encountered in a filename.

probe.py: `probe()` returned `{}` on error paths but callers iterate the
return value as a list. Changed both early-return paths to `[]`.
Also replaces deprecated `logger.warn()` with `logger.warning()`.

zz_remux/zz_remux/probe.py

@@ -18,8 +18,8 @@ class Probe:
 
     # Sanity
     if not path.exists():
-      self.logger.warn(f"No such file: {path}")
-      return {}
+      self.logger.warning(f"No such file: {path}")
+      return []
 
     # ffprobe
     probe = self.proc.run([
@@ -42,7 +42,7 @@ class Probe:
       err = f"Stream missing index: {path}"
     if err is not None:
       self.logger.error(err)
-      return {}
+      return []
 
     # Return
     self.logger.debug(f"Streams: {streams}")

zz_remux/zz_remux/scan.py

@@ -46,7 +46,7 @@ class Scan:
           info['lang'] = lang.to_alpha3()
         except:
           if m.group(2):
-            logger.warning(f"Unable to match language code: {m.group(2)}")
+            self.logger.warning(f"Unable to match language code: {m.group(2)}")
 
         if m.group(3):
           info['sdh'] = m.group(3).lower() in Consts.subs_sdh