Fix errors in line buffer code

lib/nntp/tiny/buffer.py

@@ -1,3 +1,5 @@
+import socket
+
 class BufferOverflow(Exception):
     def __init__(self):
         super().__init__("Buffer overflow")
@@ -17,7 +19,7 @@ class LineBuffer():
             # Check and see if there is already a line in the
             # internal buffer.
             #
-            offset = self.buf.find(b'\n', self.offset, self.count)
+            offset = self.buf.find(b'\n', self.offset, len(self.buf))
 
             if offset < 0:
                 #