debian: add a hard dependency on logsave to e2fsprogs

debian: add a hard dependency on logsave to e2fsprogs

The initramfs created by the initramfs-tools package needs logsave and
assumes it comes along with e2fsprogs.  If it is not present, the
result systems which will fail to boot.  Fix this by adding the
dependency.

In the future initramfs-tools will explicitly ask for logsave (tracked
in Debian Bug: #932854), but we'll need to keep this dependency until
the next stable release of Debian.

Addresses-Debian-Bug: #932855
Addresses-Debian-Bug: #932859
Addresses-Debian-Bug: #932861
Addresses-Debian-Bug: #932881
Addresses-Debian-Bug: #932888

Signed-off-by: Theodore Ts'o <tytso@mit.edu>