drm: don't check modeset locks in panic handler

drm: don't check modeset locks in panic handler

commit a9b054e8ab06504c2afa0e307ee78d3778993a1d upstream.

Since we know that locking is broken in that case and it's more
important to not flood the dmesg with random gunk.

Reported-and-tested-by: Borislav Petkov <bp@suse.de>
References: http://lkml.kernel.org/r/20130502000206.GH15623@pd.tnic
Cc: Dave Airlie <airlied@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>