scons: Use only the shared object name when linking progs.

Otherwise the whole path gets baked into the executable.
diff --git a/progs/SConscript b/progs/SConscript
index 66a1745..2ec95a2 100644
--- a/progs/SConscript
+++ b/progs/SConscript
@@ -23,7 +23,8 @@
 		progs_env.Prepend(LIBS = ['GLU', 'GL'])
 
 	# Glut
-	progs_env.Prepend(LIBS = [glut])
+	progs_env.Prepend(LIBPATH = [glut.dir])
+	progs_env.Prepend(LIBS = [glut.name])
 
 	# GLEW
 	progs_env.Prepend(LIBS = [glew])