glsl: Fix Doxygen tag \file in recently renamed files
diff --git a/src/glsl/opt_constant_propagation.cpp b/src/glsl/opt_constant_propagation.cpp
index 5d875b7..6719fc8 100644
--- a/src/glsl/opt_constant_propagation.cpp
+++ b/src/glsl/opt_constant_propagation.cpp
@@ -22,7 +22,7 @@
  */
 
 /**
- * \file ir_constant_propagation.cpp
+ * \file opt_constant_propagation.cpp
  *
  * Tracks assignments of constants to channels of variables, and
  * usage of those constant channels with direct usage of the constants.