Better function to count lines in a file
Better function to count lines in a file

The existing _file_length function does not properly handle cases
when the file has no lines in it.  You'll get the following error:

UnboundLocalError: local variable 'line' referenced before assignment

This patch simplifies the function into a one liner to count line
numbers.

Change-Id: I427253989ec8bffaa423054616fbb4d1425eb031

stackforge/bandit,stackforge/bandit,chair6/bandit,pombredanne/bandit,pombredanne/bandit