remove warning

was having: "vp8/encoder/onyx_if.c:5365: warning: comparison of unsigned expression >= 0 is always true"

vp8/encoder/onyx_if.c

@@ -5362,12 +5362,12 @@ int vp8_set_internal_size(VP8_PTR comp, VPX_SCALING horiz_mode, VPX_SCALING vert
 {
     VP8_COMP *cpi = (VP8_COMP *) comp;
 
-    if (horiz_mode >= NORMAL && horiz_mode <= ONETWO)
+    if (horiz_mode <= ONETWO)
         cpi->common.horiz_scale = horiz_mode;
     else
         return -1;
 
-    if (vert_mode >= NORMAL && vert_mode <= ONETWO)
+    if (vert_mode <= ONETWO)
         cpi->common.vert_scale  = vert_mode;
     else
         return -1;