cogl-sub-texture: Fix the height of sub textures
cogl-sub-texture: Fix the height of sub textures

The code which is used to get the texture height was accidentally
using the width due to a cut-and-paste fail.

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