fix the following warnings:

src/GLContext.c:1066:16: warning: extra tokens at end of #ifndef directive [-Wextra-tokens]
#ifndef IS_EGL #RT-25058

fix warnings on prism-es2-native (mac)
src/GLPixelFormat.c:43:31: warning: argument to 'sizeof' in 'memset' call is the same expression as the destination; did you mean to dereference it? [-Wsizeof-pointer-memaccess]
    memset(pfInfo, 0, sizeof (pfInfo));
           ~~~~~~ ^~~~~~