Avoid a compiler warning.

dlls/x11drv/dib.c

@@ -4284,13 +4284,13 @@ static LONG CALLBACK X11DRV_DIB_FaultHandler( PEXCEPTION_POINTERS ep )
 {
     X_PHYSBITMAP *physBitmap = NULL;
     BOOL found = FALSE;
-    const BYTE *addr;
+    BYTE *addr;
     struct list *ptr;
 
     if (ep->ExceptionRecord->ExceptionCode != EXCEPTION_ACCESS_VIOLATION)
         return EXCEPTION_CONTINUE_SEARCH;
 
-    addr = (const BYTE*)ep->ExceptionRecord->ExceptionInformation[1];
+    addr = (BYTE *)ep->ExceptionRecord->ExceptionInformation[1];
 
     EnterCriticalSection(&dibs_cs);
     LIST_FOR_EACH( ptr, &dibs_list )

dlls/x11drv/x11drv.h

@@ -113,7 +113,7 @@ typedef struct
     XShmSegmentInfo shminfo;        /* shared memory segment info */
 #endif
     struct list   entry;            /* Entry in global DIB list */
-    const BYTE   *base;             /* Base address */
+    BYTE         *base;             /* Base address */
     SIZE_T        size;             /* Size in bytes */
 } X_PHYSBITMAP;