m68k: mac: Fix typos in comments

Delete the redundant word 'an'.
The second "and" should not be deleted, but replaced by "an".

Signed-off-by: Xiang wangx <wangxiang@cdjrlc.com>
Link: https://lore.kernel.org/r/20220610083924.32877-1-wangxiang@cdjrlc.com


Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>