tools: Drop unnecessary use of __file__

There are few places where the path of the current modules is calculated
but not used. Drop them.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/entry.py b/tools/binman/entry.py
index 3434a3f..c17a989 100644
--- a/tools/binman/entry.py
+++ b/tools/binman/entry.py
@@ -16,8 +16,6 @@
 
 modules = {}
 
-our_path = os.path.dirname(os.path.realpath(__file__))
-
 
 # An argument which can be passed to entries on the command line, in lieu of
 # device-tree properties.
diff --git a/tools/buildman/test.py b/tools/buildman/test.py
index 3eaba07..1a259d5 100644
--- a/tools/buildman/test.py
+++ b/tools/buildman/test.py
@@ -9,9 +9,6 @@
 import time
 import unittest
 
-# Bring in the patman libraries
-our_path = os.path.dirname(os.path.realpath(__file__))
-
 from buildman import board
 from buildman import bsettings
 from buildman import builder
diff --git a/tools/rmboard.py b/tools/rmboard.py
index 06c3562..de68563 100755
--- a/tools/rmboard.py
+++ b/tools/rmboard.py
@@ -28,9 +28,6 @@
 import re
 import sys
 
-# Bring in the patman libraries
-our_path = os.path.dirname(os.path.realpath(__file__))
-
 from patman import command
 
 def rm_kconfig_include(path):