r300g/radeong: fix scons build

src/gallium/drivers/r300/SConscript

@@ -24,6 +24,7 @@ r300 = env.ConvenienceLibrary(
         'r300_query.c',
         'r300_render.c',
         'r300_screen.c',
+        'r300_screen_buffer.c',
         'r300_state.c',
         'r300_state_derived.c',
         'r300_state_invariant.c',

src/gallium/targets/dri-radeong/SConscript

@@ -8,14 +8,10 @@ env = drienv.Clone()
 
 env.ParseConfig('pkg-config --cflags --libs libdrm_radeon')
 
-drivers = [
-    trace,
-    softpipe,
-    r300
-]
+drivers = r300 + trace + softpipe
 
 env.SharedLibrary(
     target ='radeon_dri.so',
     source = COMMON_GALLIUM_SOURCES,
-    LIBS = st_dri + radeonwinsys + mesa + drivers + gallium + env['LIBS'],
+    LIBS = st_dri + radeonwinsys + mesa + glsl + drivers + gallium + env['LIBS'],
 )