st/mesa: Make st_cb_blit.h FEATURE_EXT_framebuffer_blit aware.

This change allows st_cb_blit.h to be used without knowing if
FEATURE_EXT_framebuffer_blit is enabled.

src/mesa/state_tracker/st_cb_blit.h

@@ -29,18 +29,28 @@
 #define ST_CB_BLIT_H
 
 
+#include "main/mtypes.h"
 #include "st_context.h"
 
 
-
 extern void
 st_init_blit(struct st_context *st);
 
 extern void
 st_destroy_blit(struct st_context *st);
 
+#if FEATURE_EXT_framebuffer_blit
+
 extern void
 st_init_blit_functions(struct dd_function_table *functions);
 
+#else
+
+static INLINE void
+st_init_blit_functions(struct dd_function_table *functions)
+{
+}
+
+#endif /* FEATURE_EXT_framebuffer_blit */
 
 #endif /* ST_CB_BLIT_H */