server: Fix a typo in the enumeration of the ACE's in sd_to_mode.

This caused only the first ACE to be examined, causing permissions to 
always be set to ----???---.
diff --git a/server/file.c b/server/file.c
index 7f34c02..58973c0 100644
--- a/server/file.c
+++ b/server/file.c
@@ -421,7 +421,7 @@
     {
         const ACE_HEADER *ace = (const ACE_HEADER *)(dacl + 1);
         ULONG i;
-        for (i = 0; i < dacl->AceCount; i++, ace_next( ace ))
+        for (i = 0; i < dacl->AceCount; i++, ace = ace_next( ace ))
         {
             const ACCESS_ALLOWED_ACE *aa_ace;
             const ACCESS_DENIED_ACE *ad_ace;