vrend: Replace glTexParameterf() with glTexParameteri() for GL_TEXTURE_MIN/MAG_FILTER.
requested to merge spexius/virglrenderer:ticket_212_replace_gltexparameterf_with_gltexparameteri into master
GL_TEXTURE_MIN/MAG_FILTER expects an enum value, to be set with glTexParameteri() (integer value) instead of glTexParameterf() (float value).