The number of columns relates to the width, not the height.  Use the
correct variable.
Signed-off-by: John Keeping <jkeeping@inmusicbrands.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Fixes: fdd591e00a9c ("drm/ssd130x: Add support for the SSD132x OLED controller family")
Link: https://lore.kernel.org/r/20250611111307.1814876-1-jkeeping@inmusicbrands.com
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
 
 static void ssd132x_clear_screen(struct ssd130x_device *ssd130x, u8 *data_array)
 {
-       unsigned int columns = DIV_ROUND_UP(ssd130x->height, SSD132X_SEGMENT_WIDTH);
+       unsigned int columns = DIV_ROUND_UP(ssd130x->width, SSD132X_SEGMENT_WIDTH);
        unsigned int height = ssd130x->height;
 
        memset(data_array, 0, columns * height);