- Don't crash if we are already freed

- Some code frees the buffers right after an operation fails which is fine

svn path=/branches/aicom-network-fixes/; revision=35297

drivers/network/afd/afd/lock.c

@@ -112,6 +112,8 @@ VOID UnlockBuffers( PAFD_WSABUF Buf, UINT Count, BOOL Address ) {
     PAFD_MAPBUF Map = (PAFD_MAPBUF)(Buf + Count + Lock);
     UINT i;
 
+    if( !Buf ) return;
+
     for( i = 0; i < Count + Lock; i++ ) {
 	if( Map[i].Mdl ) {
 	    MmUnlockPages( Map[i].Mdl );