bisect: further style nitpicks
bisect: further style nitpicks

Fix a few remaining lines that indented with spaces.

Also simplify the logic of checking out the original branch and reporting
error during "bisect reset".

Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git