shell32: Write-strings warnings fix (2 of 2)

[Andrew Talbot]

Changelog:
    shell32: Write-strings warnings fix.

diff -urN a/dlls/shell32/shellord.c b/dlls/shell32/shellord.c
--- a/dlls/shell32/shellord.c	2006-07-16 15:08:30.000000000 +0100
+++ b/dlls/shell32/shellord.c	2006-08-07 19:00:16.000000000 +0100
@@ -522,7 +522,7 @@
  * RETURNS
  *   result of the SHQueryValueEx call
  */
-static INT SHADD_get_policy(LPSTR policy, LPDWORD type, LPVOID buffer, LPDWORD len)
+static INT SHADD_get_policy(LPCSTR policy, LPDWORD type, LPVOID buffer, LPDWORD len)
 {
     HKEY Policy_basekey;
     INT ret;