emmc-log: Remove latest journal to fit run log
Use --vacuum-files to remove the oldest journal file until there are
enough space for the run logs... instead of vacuum by size.
Tested:
```
root@dddfz27-nfd01:~# /usr/bin/emmc_logging.sh
Didn't detect eMMC log network enable flag. Start persistent eMMC log and then exit.
Stop rsyslog before migrating to eMMC to make sure we don't send out logs during transition
Warning: Stopping rsyslog.service, but it can still be activated by:
syslog.socket
# For Testing only
Setting max to 90MB
Vacuuming done, freed 0B of archived journals from /mnt/luks-mmcblk0_fs/logs.
Deleted archived journal /mnt/luks-mmcblk0_fs/logs/7485042ce69d4253991f117bd4cc2875/system@e064ed7512cf42779f13b691a3c2aa10-00000000000a9f26-00061150bb5e66d9.journal (15.8M).
Vacuuming done, freed 15.8M of archived journals from /mnt/luks-mmcblk0_fs/logs/7485042ce69d4253991f117bd4cc2875.
Flushing journal logs to eMMC
Journald is now logging to eMMC
```
Google-Bug-Id: 299976757
Change-Id: Ia1c96fb3f05790fc23e624c0b43c9271791d28a0
Signed-off-by: Willy Tu <wltu@google.com>
1 file changed
