st/mesa: use new _mesa_expand_bitmap() function

src/mesa/state_tracker/st_cb_bitmap.c

 /**
  * Copy user-provide bitmap bits into texture buffer, expanding
  * bits into texels.
- * "On" bits will set texels to 0xff.
+ * "On" bits will set texels to 0x0.
  * "Off" bits will not modify texels.
  * Note that the image is actually going to be upside down in
  * the texture.  We deal with that with texcoords.
               const GLubyte *bitmap,
               ubyte *destBuffer, uint destStride)
 {
-   GLint row, col;
-
-#define SET_PIXEL(COL, ROW) \
-   destBuffer[(py + (ROW)) * destStride + px + (COL)] = 0x0;
-
-   for (row = 0; row < height; row++) {
-      const GLubyte *src = (const GLubyte *) _mesa_image_address2d(unpack,
-                 bitmap, width, height, GL_COLOR_INDEX, GL_BITMAP, row, 0);
-
-      if (unpack->LsbFirst) {
-         /* Lsb first */
-         GLubyte mask = 1U << (unpack->SkipPixels & 0x7);
-         for (col = 0; col < width; col++) {
-
-            if (*src & mask) {
-               SET_PIXEL(col, row);
-            }
-
-            if (mask == 128U) {
-               src++;
-               mask = 1U;
-            }
-            else {
-               mask = mask << 1;
-            }
-         }
-
-         /* get ready for next row */
-         if (mask != 1)
-            src++;
-      }
-      else {
-         /* Msb first */
-         GLubyte mask = 128U >> (unpack->SkipPixels & 0x7);
-         for (col = 0; col < width; col++) {
-
-            if (*src & mask) {
-               SET_PIXEL(col, row);
-            }
-
-            if (mask == 1U) {
-               src++;
-               mask = 128U;
-            }
-            else {
-               mask = mask >> 1;
-            }
-         }
-
-         /* get ready for next row */
-         if (mask != 128)
-            src++;
-      }
-
-   } /* row */
+   destBuffer += py * destStride + px;
 
-#undef SET_PIXEL
+   _mesa_expand_bitmap(width, height, unpack, bitmap,
+                       destBuffer, destStride, 0x0);
 }