scons: Don't link program_lexer.l/y twice.

program/lex.yy.c and program/program_parse.tab.c is already included in
the PROGRAM_FILES variable.

We still need to specify the dependency relationship though.

Reviewed-by: Brian Paul <brianp@vmware.com>
diff --git a/src/mesa/SConscript b/src/mesa/SConscript
index 81939f9..cc5d242 100644
--- a/src/mesa/SConscript
+++ b/src/mesa/SConscript
@@ -40,17 +40,12 @@
 source_lists = env.ParseSourceList('Makefile.sources')
 
 env.Append(YACCFLAGS = '-d -p "_mesa_program_"')
-program_lex = env.CFile('program/lex.yy.c', 'program/program_lexer.l')
-program_parse = env.CFile('program/program_parse.tab.c',
-                          'program/program_parse.y')
-program_sources = source_lists['PROGRAM_FILES'] + [
-    program_lex,
-    program_parse[0],
-]
+env.CFile('program/lex.yy.c', 'program/program_lexer.l')
+env.CFile('program/program_parse.tab.c', 'program/program_parse.y')
 
 mesa_sources = (
     source_lists['MESA_FILES'] +
-    program_sources +
+    source_lists['PROGRAM_FILES'] +
     source_lists['STATETRACKER_FILES']
 )