glsl: remove never true do_dead_code() parameter

Since we have now switched all drivers to using NIR and therefore
the NIR based uniform linker this param never needs to be set to
true so remove it.

Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16924>

src/compiler/glsl/opt_dead_code.cpp

@@ -43,7 +43,7 @@ static bool debug = false;
  * for usage on an unlinked instruction stream.
  */
 bool
-do_dead_code(exec_list *instructions, bool uniform_locations_assigned)
+do_dead_code(exec_list *instructions)
 {
    ir_variable_refcount_visitor v;
    bool progress = false;
@@ -122,12 +122,11 @@ do_dead_code(exec_list *instructions, bool uniform_locations_assigned)
 	  */
 
 	 /* uniform initializers are precious, and could get used by another
-	  * stage.  Also, once uniform locations have been assigned, the
-	  * declaration cannot be deleted.
+	  * stage.
 	  */
          if (entry->var->data.mode == ir_var_uniform ||
              entry->var->data.mode == ir_var_shader_storage) {
-            if (uniform_locations_assigned || entry->var->constant_initializer)
+            if (entry->var->constant_initializer)
                continue;
 
             /* Section 2.11.6 (Uniform Variables) of the OpenGL ES 3.0.3 spec
@@ -188,12 +187,7 @@ do_dead_code_unlinked(exec_list *instructions)
       ir_function *f = ir->as_function();
       if (f) {
 	 foreach_in_list(ir_function_signature, sig, &f->signatures) {
-	    /* The setting of the uniform_locations_assigned flag here is
-	     * irrelevent.  If there is a uniform declaration encountered
-	     * inside the body of the function, something has already gone
-	     * terribly, terribly wrong.
-	     */
-	    if (do_dead_code(&sig->body, false))
+	    if (do_dead_code(&sig->body))
 	       progress = true;
 	 }
       }