fbcon: Use oops_in_progress instead of panic_cpu

fbcon: Use oops_in_progress instead of panic_cpu

Panic_cpu is not exported, so it can't be used if fbcon is used as
a module. Use oops_in_progress in this case, but non-fatal oops won't
be printed.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202407210203.2ISiIC9m-lkp@intel.com/
Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20240722114800.174558-1-jfalempe@redhat.com