The tag is present in Lintian version 2.104.234. That is the most recent version we know about.
The given .la file points to a libdir other than the path where it is
installed. This can be caused by resetting
prefix at make install
time instead of using
DESTDIR. The incorrect path will cause
packages linking to this library using libtool to build incorrectly (adding
incorrect paths to RPATH, for example).