drm/panic: Fix divide by 0 if the screen width < font width

In the unlikely case that the screen is tiny, and smaller than the
font width, it leads to a divide by 0:

draw_line_with_wrap()
chars_per_row = sb->width / font->width = 0
line_wrap.len = line->len % chars_per_row;

This will trigger a divide by 0

Reviewed-by: Javier Martinez Canillas <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jocelyn Falempe <[email protected]>

Author: Jocelyn Falempe

drivers/gpu/drm/drm_panic.c

@@ -523,7 +523,7 @@ static void draw_panic_static_kmsg(struct drm_scanout_buffer *sb)
 	struct drm_panic_line line;
 	int yoffset;
 
-	if (!font)
+	if (!font || font->width > sb->width)
 		return;
 
 	yoffset = sb->height - font->height - (sb->height % font->height) / 2;