drm/log: Fix infinite loop when scale is too large for display

In the Linux kernel, the following vulnerability has been resolved: drm/log: Fix infinite loop when scale is too large for display When scale is large enough that scaled_font exceeds the display dimensions, rows or columns become 0. A columns value of 0 causes an infinite loop in drm_log_draw_kmsg_record() because the loop never decrements len. Check for zero rows/columns in drm_log_setup_modeset() and return an error, cleaning up the already allocated buffer to avoid a leak.