debian: fix dpkg-buildpackage for Debian Squeeze

debian: fix dpkg-buildpackage for Debian Squeeze

Commit becb01ce84d breaks building e2fsprogs with dpkg 1.15.8 which is
used in Debian 6.0 (Squeeze), since it doesn't support package
specifications qualified with an architecture (i.e., "dpkg-query -W
libblkid1:amd64").

Debian only needs to use its own version of libblkid and libuuid for
versions of Debian 5.0 (Lenny) or before.  So default to using
util-linux-ng, instead of trying to test the version number of
libblkid1.

Lenny was released in February, 2009, and the current stable Debian
release is 7.x, so it is two stable releases back as of February 2014.
In the unlikely case someone needs to build a modern version of
e2fsprogs on a version of Debian which is five years old or older, can
create the file Debian/rules.custom with the line:

UTIL_LINUX_NG = no

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