um: remove unneeded semicolon in um_arch.c

Fix following coccicheck warning:
./arch/um/kernel/um_arch.c:284:34-35: Unneeded semicolon

Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
1 file changed