shell32: Mark a fall-through in a switch statement

[Andrew Talbot]

Changelog:
    shell32: Mark a fall-through in a switch statement.

diff --git a/dlls/shell32/shelldispatch.c b/dlls/shell32/shelldispatch.c
index 0ad3b1d..f8668ef 100644
--- a/dlls/shell32/shelldispatch.c
+++ b/dlls/shell32/shelldispatch.c
@@ -705,6 +705,7 @@ static HRESULT Folder_Constructor(VARIANT *dir, Folder **ppsdf)
                 !PathIsRelativeW(V_BSTR(dir)) &&
                 PathFileExistsW(V_BSTR(dir)))
                 break;
+            /* fall through */
         default:
             return S_FALSE;
     }