cabinet: Write-strings warning fix

[Andrew Talbot]

Changelog:
    cabinet: Write-strings warning fix.

diff -urN a/dlls/cabinet/cabinet_main.c b/dlls/cabinet/cabinet_main.c
--- a/dlls/cabinet/cabinet_main.c	2006-05-23 13:47:35.000000000 +0100
+++ b/dlls/cabinet/cabinet_main.c	2006-07-29 14:35:05.000000000 +0100
@@ -303,6 +303,7 @@
     HRESULT res = S_OK;
     HFDI hfdi;
     ERF erf;
+    static CHAR empty[] = "";
 
     TRACE("(%p, %s)\n", dest, szCabName);
 
@@ -322,7 +323,7 @@
     if (GetFileAttributesA(dest->directory) == INVALID_FILE_ATTRIBUTES)
         return S_OK;
 
-    if (!FDICopy(hfdi, (LPSTR)szCabName, "", 0,
+    if (!FDICopy(hfdi, (LPSTR)szCabName, empty, 0,
          fdi_notify_extract, NULL, dest))
         res = E_FAIL;