python: fix flake8 warnings and format with black

Most of the flake8 warnings in this repository were fairly trivial,
so fixed them.  The "openbmctool" is 7000+ lines of pretty heavily
warned code, so just disabling that one.  Format everything with
black.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Icb3f6ee9bf03dece58785f7af00617c87a84aa65
diff --git a/dbus-vis/linecount.py b/dbus-vis/linecount.py
index ef7dd83..e3d98fc 100644
--- a/dbus-vis/linecount.py
+++ b/dbus-vis/linecount.py
@@ -1,8 +1,9 @@
 # This script is used for printing out the number of packets in a pcap file
 
-from scapy.all import rdpcap
 import sys
 
+from scapy.all import rdpcap
+
 file_name = sys.argv[1]
 try:
     stream = rdpcap(file_name)
@@ -10,5 +11,5 @@
     for packet in stream:
         n += 1
     print(n)
-except Exception as e:
+except Exception:
     pass