Fix the following coccicheck warnings:

./arch/s390/kernel/perf_cpum_cf.c:272:2-3: Unneeded semicolon.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/1614233736-87331-1-git-send-email-jiapeng.chong@linux.alibaba.comSigned-off-by: Heiko Carstens <hca@linux.ibm.com>