FFDC code fix using pyflake

Changes:
   - Fixed the following error
     ffdc/ffdc_collector.py:56:9:
     local variable 'e' is assigned to but never used

     ffdc/ffdc_collector.py:913:21: undefined name 'self'
     ffdc/ffdc_collector.py:918:21: undefined name 'self'
     ffdc/ffdc_collector.py:1356:9:
     local variable 'env_vars_list' is assigned to but never used

     ffdc/lib/ssh_utility.py:67:9:
     local variable 'e' is assigned to but never used

     ffdc/plugins/redfish.py:8:1: 'os' imported but unused

Tested:
   - pyflake ffdc/
   - Tested the changes on sandbox
Change-Id: Ib4e774e1e7e16b49a36a5a00e35d6e60b4868715
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/ffdc/lib/ssh_utility.py b/ffdc/lib/ssh_utility.py
index 77ad8bb..73cdd9c 100644
--- a/ffdc/lib/ssh_utility.py
+++ b/ffdc/lib/ssh_utility.py
@@ -72,6 +72,7 @@
             socket.error,
         ) as e:
             is_ssh_login = False
+            print("SSH Login: Exception: %s" % e)
 
         return is_ssh_login