cogl-object-private.h: white space cleanup
cogl-object-private.h: white space cleanup

simply replaces tabs with spaces

spatulasnout/cogl,collects/cogl,djdeath/cogl,Distrotech/cogl,gcampax/cogl,collects/cogl,djdeath/cogl,Distrotech/cogl,gcampax/cogl,Distrotech/cogl,spatulasnout/cogl,gcampax/cogl,djdeath/cogl-android,djdeath/cogl-android,djdeath/cogl-android,Distrotech/cogl,gcampax/cogl,djdeath/cogl