s390/kernel: fix a typo

s/struture/structure/

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Link: https://lore.kernel.org/r/20210322062500.3109603-1-unixbhaskar@gmail.com


Signed-off-by: Heiko Carstens <hca@linux.ibm.com>