[TextLayer] Simplify building of the *expanded* transform in `expandTextDivs`
[TextLayer] Simplify building of the *expanded* transform in `expandTextDivs`

Rather than essentially re-computing the `originalTransform` every time, we can simply use it directly instead.

nawawi/pdf.js,caremerge/pdf.js,macroplant/pdf.js,showpad/mozilla-pdf.js,Shoobx/pdf.js,nawawi/pdf.js,caremerge/pdf.js,mozilla/pdf.js,xavier114fch/pdf.js,Snuffleupagus/pdf.js,Shoobx/pdf.js,showpad/mozilla-pdf.js,Snuffleupagus/pdf.js,mainegreen/pdf.js,timvandermeij/pdf.js,mozilla/pdf.js,timvandermeij/pdf.js,mainegreen/pdf.js,mozilla/pdf.js,showpad/mozilla-pdf.js,xavier114fch/pdf.js,Snuffleupagus/pdf.js,macroplant/pdf.js,nawawi/pdf.js,timvandermeij/pdf.js,macroplant/pdf.js,Shoobx/pdf.js