gl: fix the use of always-defined macros

After 2a0f0399ae GST_GL_* macros are always
defined to 0 or 1. Don't use #ifdef ... or #if defined() on them.

https://bugzilla.gnome.org/show_bug.cgi?id=726591

gst-libs/gst/gl/egl/gstglcontext_egl.c

@@ -173,7 +173,7 @@ gst_gl_context_egl_choose_config (GstGLContextEGL * egl,
     config_attrib[i++] = EGL_OPENGL_ES2_BIT;
   else
     config_attrib[i++] = EGL_OPENGL_BIT;
-#if defined(USE_EGL_RPI) && defined(GST_GL_HAVE_WINDOW_WAYLAND)
+#if defined(USE_EGL_RPI) && GST_GL_HAVE_WINDOW_WAYLAND
   /* The configurations r=5 g=6 b=5 seems to be buggy whereas
    * it works when using dispmanx directly */
   config_attrib[i++] = EGL_BUFFER_SIZE;
@@ -485,7 +485,7 @@ gst_gl_context_egl_get_proc_address (GstGLContext * context, const gchar * name)
   gpointer result = NULL;
 
   /* FIXME: On Android this returns wrong addresses for non-EGL functions */
-#ifdef GST_GL_HAVE_WINDOW_ANDROID
+#if GST_GL_HAVE_WINDOW_ANDROID
   if (!(result = gst_gl_context_default_get_proc_address (context, name))) {
     if (g_str_has_prefix (name, "egl"))
       result = eglGetProcAddress (name);

gst-libs/gst/gl/glprototypes/gstgl_compat.h

@@ -24,16 +24,16 @@
 #include <gst/gl/gstglconfig.h>
 
 /* undefined typedefs */
-#ifndef GST_GL_HAVE_GLEGLIMAGEOES
+#if !GST_GL_HAVE_GLEGLIMAGEOES
 typedef gpointer GLeglImageOES;
 #endif
-#ifndef GST_GL_HAVE_GLCHAR
+#if !GST_GL_HAVE_GLCHAR
 typedef gchar GLchar;
 #endif
-#ifndef GST_GL_HAVE_GLSIZEIPTR
+#if !GST_GL_HAVE_GLSIZEIPTR
 typedef ptrdiff_t GLsizeiptr;
 #endif
-#ifndef GST_GL_HAVE_GLINTPTR
+#if !GST_GL_HAVE_GLINTPTR
 typedef ptrdiff_t GLintptr;
 #endif