reboot: only run fsck when detecting filesystem inconsistency

Running fsck when filesystem is in clean state is unnecessary
and causes long shutdown duration.

Bug: 120575926
Test: shutdown
Change-Id: I0562bdad4ac2fb2dd3c9617f96ca3d6279876bd8
Signed-off-by: Randall Huang <huangrandall@google.com>
1 file changed