Fix various whitespace issues reported by pyflakes

- E201 whitespace after '['
- E202 whitespace before '}'
- E221 multiple spaces before operator
- E222 multiple spaces after operator
- E225 missing whitespace around operator
- E226 missing whitespace around arithmetic operator
- E231 missing whitespace after ','
- E261 at least two spaces before inline comment
- E271 multiple spaces after keyword

Fixed automatically with autopep8:

  git ls-files | grep py$ | xargs autopep8 --in-place \
    --select E201,E202,E221,E222,E225,E226,E231,E261,E271

Change-Id: I367113eb8c847eb460532c7c2f8643f33040308c
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/254601
Reviewed-by: Mike Frysinger <vapier@google.com>
Tested-by: David Pursehouse <dpursehouse@collab.net>

subcmds/abandon.py

@@ -79,10 +79,10 @@ It is equivalent to "git branch -D <branchname>".
 
     if err:
       for br in err.keys():
-        err_msg = "error: cannot abandon %s" %br
+        err_msg = "error: cannot abandon %s" % br
         print(err_msg, file=sys.stderr)
         for proj in err[br]:
-          print(' '*len(err_msg) + " | %s" % proj.relpath, file=sys.stderr)
+          print(' ' * len(err_msg) + " | %s" % proj.relpath, file=sys.stderr)
       sys.exit(1)
     elif not success:
       print('error: no project has local branch(es) : %s' % nb,
@@ -95,5 +95,5 @@ It is equivalent to "git branch -D <branchname>".
           result = "all project"
         else:
           result = "%s" % (
-            ('\n'+' '*width + '| ').join(p.relpath for p in success[br]))
-        print("%s%s| %s\n" % (br,' '*(width-len(br)), result),file=sys.stderr)
+            ('\n' + ' ' * width + '| ').join(p.relpath for p in success[br]))
+        print("%s%s| %s\n" % (br, ' ' * (width - len(br)), result), file=sys.stderr)