twister: fixed pylint issues

Fixed import and unused variable warning.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

scripts/footprint/compare_footprint

@@ -125,7 +125,7 @@ def run_sanity_footprint(commit=None, cwd=os.environ.get('ZEPHYR_BASE'),
 
     proc = subprocess.Popen(cmd, stdout=subprocess.PIPE,
                             cwd=cwd, shell=True)
-    output,error=proc.communicate()
+    output,_ = proc.communicate()
     if proc.wait() == 0:
         logger.debug(output)
         return True

scripts/pylib/twister/scl.py

@@ -3,6 +3,8 @@
 # SPDX-License-Identifier: Apache-2.0
 # Zephyr's Sanity Check library
 #
+# pylint: disable=unused-import
+#
 # Set of code that other projects can also import to do things on
 # Zephyr's sanity check testcases.