kernel: md: raid1: fix potential OOB in raid1_remove_disk()

In the Linux kernel, the following vulnerability has been resolved: md: raid1: fix potential OOB in raid1removedisk If rddev-raiddisk is greater than mddev-raiddisks, there will be an out-of-bounds in raid1removedisk. We have already found similar reports as follows: 1 commit d17f744e883b...