cogl-texture: Fix manual repeating for negative coordinates
cogl-texture: Fix manual repeating for negative coordinates

When calculating the next integer position for negative coordinates it
would not increment if the position is already a multiple of one so we
need to manually add one.

djdeath/clutter-multithreaded,GNOME/clutter,spatulasnout/clutter,dlespiau/clutter,djdeath/clutter,ebassi/clutter,collects/clutter,heysion/clutter-clone,jigpu/clutter,djdeath/clutter,nobled/clutter,kerrickstaley/clutter-vala,heysion/clutter-clone,djdeath/clutter-android,Distrotech/clutter,nobled/clutter,dlespiau/clutter,djdeath/clutter-multithreaded,djdeath/clutter,rkudiyarov/clutter_osx,djdeath/clutter-android,djdeath/clutter-android,spatulasnout/clutter,rkudiyarov/clutter_osx,jigpu/clutter,kerrickstaley/clutter-vala,GNOME/clutter,collects/clutter,heysion/clutter-clone,dlespiau/clutter,ebassi/clutter,heysion/clutter-clone,rkudiyarov/clutter_osx,spatulasnout/clutter,kerrickstaley/clutter-vala,djdeath/clutter,Distrotech/clutter,kerrickstaley/clutter-vala,Distrotech/clutter,GNOME/clutter,collects/clutter,Distrotech/clutter,heysion/clutter-clone,rkudiyarov/clutter_osx,spatulasnout/clutter,ebassi/clutter,djdeath/clutter-multithreaded,spatulasnout/clutter,jigpu/clutter,djdeath/clutter,ebassi/clutter,nobled/clutter,djdeath/clutter-multithreaded,jigpu/clutter,collects/clutter,djdeath/clutter-android,ebassi/clutter,jigpu/clutter,Distrotech/clutter,djdeath/clutter,collects/clutter,Distrotech/clutter,GNOME/clutter,GNOME/clutter,djdeath/clutter-android,jigpu/clutter