cryptui: fix a compiler warning on PC-BSD

[Austin English]

main.c: In function 'cert_properties_general_dlg_proc':
main.c:3340: warning: 'purposeSelection' may be used uninitialized in
this function
main.c:3340: note: 'purposeSelection' was declared here

-- 
-Austin
-------------- next part --------------
diff --git a/dlls/cryptui/main.c b/dlls/cryptui/main.c
index ddbea8e..f29f1e6 100644
--- a/dlls/cryptui/main.c
+++ b/dlls/cryptui/main.c
@@ -3337,7 +3337,7 @@ static void show_cert_usages(HWND hwnd, struct edit_cert_data *data)
     DWORD size;
     RECT rc;
     LVCOLUMNW column;
-    PurposeSelection purposeSelection;
+    PurposeSelection purposeSelection = PurposeEnableAll;
 
     GetWindowRect(lv, &rc);
     column.mask = LVCF_WIDTH;