Fix snake case compiler warning
Fix snake case compiler warning

Since the function in question directly mimics an OpenGL function, I
believe disabling the warning is better than renaming the function.

bjz/glfw-rs,derekdreery/glfw-rs,servo/glfw-rs,nstoddard/glfw-rs,PistonDevelopers/glfw-rs,bvssvni/glfw-rs,derekdreery/glfw-rs,mneumann/glfw-rs,tomaka/glfw-rs