Amends the following compiler warnings:

 ```
 NXmiexpose.c:904:18: warning: ‘newValues[2].ptr’ may be used uninitialized in this function [-Wmaybe-uninitialized]
    gcval[i++].ptr = newValues[TILE].ptr;
                   ^
 NXmiexpose.c:914:24: warning: ‘newValues[1].val’ may be used uninitialized in this function [-Wmaybe-uninitialized]
       if ( pGC->fgPixel != newValues[FOREGROUND].val) {
                         ^
 ```