glsl: Initialize lower_shared_reference_visitor members.

Fix defects reported by Coverity Scan.

Uninitialized scalar field (UNINIT_CTOR)
uninit_member: Non-static class member buffer_access_type is not
initialized in this constructor nor in any functions that it
calls.
uninit_member: Non-static class member progress is not initialized
in this constructor nor in any functions that it calls.

Signed-off-by: Vinson Lee <vlee@freedesktop.org>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7243>

src/compiler/glsl/lower_shared_reference.cpp

@@ -54,7 +54,9 @@ class lower_shared_reference_visitor :
 public:
 
    lower_shared_reference_visitor(struct gl_linked_shader *shader)
-      : list_ctx(ralloc_context(NULL)), shader(shader), shared_size(0u)
+      : buffer_access_type(shared_load_access),
+      list_ctx(ralloc_context(NULL)), shader(shader), shared_size(0u),
+      progress(false)
    {
       list_inithead(&var_offsets);
    }