fbcon: Remove the superfluous break

Remove the superfluous break, as there is a 'return' before it.

Fixes: bad07ff7 ("fbcon: smart blitter usage for scrolling")
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200918010521.69950-1-jingxiangfeng@huawei.com