AK: Fix accidentally-recursive call in BitStream

Author: https://github.com/BenWiederhake
Commit: https://github.com/SerenityOS/serenity/commit/0d3a8d53973
Pull-request: https://github.com/SerenityOS/serenity/pull/3398
Reviewed-by: https://github.com/awesomekling
Reviewed-by: https://github.com/nico

AK/BitStream.h

@@ -77,7 +77,7 @@ public:
             }
         }
 
-        return discard_or_error(count);
+        return m_stream.discard_or_error(count);
     }
 
     u32 read_bits(size_t count)