'git for-each-ref --format=%(subject)' currently returns an empty string
if the log message does not contain a newline.
This patch teaches 'git for-each-ref' to return the entire log message
(instead of an empty string) if there is no newline in the log message.
Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>