Fix a build warning in compositor.rs
Fix a build warning in compositor.rs

mbrubeck/servo,DominoTree/servo,saneyuki/servo,emilio/servo,mattnenterprise/servo,thiagopnts/servo,paulrouget/servo,pyfisch/servo,ConnorGBrewster/servo,ConnorGBrewster/servo,thiagopnts/servo,eddyb/servo,pyfisch/servo,rnestler/servo,nrc/servo,upsuper/servo,dsandeephegde/servo,canaltinova/servo,DominoTree/servo,szeged/servo,SimonSapin/servo,avadacatavra/servo,notriddle/servo,notriddle/servo,avadacatavra/servo,mattnenterprise/servo,dsandeephegde/servo,dati91/servo,mbrubeck/servo,KiChjang/servo,upsuper/servo,fiji-flo/servo,thiagopnts/servo,szeged/servo,jimberlage/servo,sadmansk/servo,larsbergstrom/servo,pyfisch/servo,paulrouget/servo,nnethercote/servo,pyfisch/servo,saneyuki/servo,splav/servo,larsbergstrom/servo,larsbergstrom/servo,mbrubeck/servo,emilio/servo,jimberlage/servo,nnethercote/servo,jimberlage/servo,notriddle/servo,avadacatavra/servo,mbrubeck/servo,peterjoel/servo,mattnenterprise/servo,peterjoel/servo,DominoTree/servo,fiji-flo/servo,pyfisch/servo,larsbergstrom/servo,nrc/servo,szeged/servo,DominoTree/servo,paulrouget/servo,nnethercote/servo,jimberlage/servo,dati91/servo,DominoTree/servo,saneyuki/servo,cbrewster/servo,rnestler/servo,szeged/servo,pyfisch/servo,peterjoel/servo,saneyuki/servo,szeged/servo,anthgur/servo,anthgur/servo,peterjoel/servo,sadmansk/servo,SimonSapin/servo,thiagopnts/servo,emilio/servo,nnethercote/servo,emilio/servo,SimonSapin/servo,CJ8664/servo,DominoTree/servo,cbrewster/servo,upsuper/servo,emilio/servo,KiChjang/servo,anthgur/servo,nnethercote/servo,dsandeephegde/servo,szeged/servo,ConnorGBrewster/servo,canaltinova/servo,rnestler/servo,sadmansk/servo,dati91/servo,emilio/servo,dsandeephegde/servo,pyfisch/servo,paulrouget/servo,sadmansk/servo,szeged/servo,dsandeephegde/servo,eddyb/servo,emilio/servo,upsuper/servo,cbrewster/servo,SimonSapin/servo,larsbergstrom/servo,nnethercote/servo,rnestler/servo,larsbergstrom/servo,splav/servo,paulrouget/servo,paulrouget/servo,cbrewster/servo,thiagopnts/servo,CJ8664/servo,CJ8664/servo,notriddle/servo,eddyb/servo,SimonSapin/servo,larsbergstrom/servo,cbrewster/servo,splav/servo,CJ8664/servo,CJ8664/servo,eddyb/servo,sadmansk/servo,thiagopnts/servo,KiChjang/servo,notriddle/servo,avadacatavra/servo,peterjoel/servo,pyfisch/servo,KiChjang/servo,dati91/servo,KiChjang/servo,mattnenterprise/servo,mbrubeck/servo,saneyuki/servo,avadacatavra/servo,upsuper/servo,paulrouget/servo,mattnenterprise/servo,nrc/servo,paulrouget/servo,saneyuki/servo,jimberlage/servo,dati91/servo,cbrewster/servo,dsandeephegde/servo,jimberlage/servo,jimberlage/servo,canaltinova/servo,fiji-flo/servo,szeged/servo,canaltinova/servo,peterjoel/servo,pyfisch/servo,nrc/servo,emilio/servo,anthgur/servo,eddyb/servo,notriddle/servo,sadmansk/servo,splav/servo,szeged/servo,eddyb/servo,canaltinova/servo,rnestler/servo,dati91/servo,larsbergstrom/servo,CJ8664/servo,paulrouget/servo,anthgur/servo,notriddle/servo,upsuper/servo,cbrewster/servo,SimonSapin/servo,fiji-flo/servo,cbrewster/servo,thiagopnts/servo,ConnorGBrewster/servo,KiChjang/servo,canaltinova/servo,emilio/servo,SimonSapin/servo,larsbergstrom/servo,nnethercote/servo,dati91/servo,rnestler/servo,fiji-flo/servo,DominoTree/servo,CJ8664/servo,fiji-flo/servo,nrc/servo,anthgur/servo,mattnenterprise/servo,fiji-flo/servo,splav/servo,larsbergstrom/servo,splav/servo,KiChjang/servo,nrc/servo,mbrubeck/servo,nnethercote/servo,saneyuki/servo,dsandeephegde/servo,avadacatavra/servo,upsuper/servo,splav/servo,DominoTree/servo,szeged/servo,DominoTree/servo,sadmansk/servo,mattnenterprise/servo,dsandeephegde/servo,peterjoel/servo,notriddle/servo,paulrouget/servo,ConnorGBrewster/servo,eddyb/servo,sadmansk/servo,saneyuki/servo,rnestler/servo,anthgur/servo,peterjoel/servo,notriddle/servo,ConnorGBrewster/servo,canaltinova/servo,mbrubeck/servo,anthgur/servo,ConnorGBrewster/servo,splav/servo,peterjoel/servo,splav/servo,jimberlage/servo,nnethercote/servo,saneyuki/servo,KiChjang/servo,KiChjang/servo,emilio/servo,fiji-flo/servo,notriddle/servo,mbrubeck/servo,eddyb/servo,rnestler/servo,splav/servo,thiagopnts/servo,CJ8664/servo,mattnenterprise/servo,DominoTree/servo,peterjoel/servo,pyfisch/servo,avadacatavra/servo,SimonSapin/servo,nrc/servo,canaltinova/servo,ConnorGBrewster/servo,KiChjang/servo,upsuper/servo,avadacatavra/servo,jimberlage/servo,saneyuki/servo,nnethercote/servo,dati91/servo