tests: Remove last GLfloat use
tests: Remove last GLfloat use

With the EGL/GLES2 types out of compositor.h this now fails to compile.

https://bugs.freedesktop.org/show_bug.cgi?id=57129

Fantu/compositor-spice,jonnylamb/weston,giucam/weston,xorgy/weston,mchalupa/weston,giucam/weston,krezovic/weston,Fantu/compositor-spice,Gnurou/weston,Gnurou/weston,xorgy/weston,Fantu/compositor-spice,eyolfson/weston,udoprog/weston,udoprog/weston,krezovic/weston,mchalupa/weston,Tarnyko/weston-xdg_surface_present,eyolfson/weston,kwm81/weston,kwm81/weston,sir-murray/weston,jonnylamb/weston,Tarnyko/weston-xdg_surface_present,sir-murray/weston