problem with info file backup restoration

[Jan Beulich]

The code in lib/am/texibuild.am uses a construct `echo "./$@" | sed 's|[^/]*$$||'` to obtain the directory of the files
to be restored. However, this obviously doesn't work when the directory is absolute (i.e. when I have the sources on
/usr/local/src and build in a separate output directory under /home). Why can't this simply be `dirname "./$@"`/ ?

Thanks, Jan