Vulnerability Advisory : mm/damon/sysfs: dealloc repeat_call_control if damon_call() fails with undefined Attack Complexity

In the Linux kernel, the following vulnerability has been resolved: mm/damon/sysfs: dealloc repeat_call_control if damon_call() fails damon_call() for repeat_call_control of DAMON_SYSFS could fail if somehow the kdamond is stopped before the damon_call(). It could happen, for example, when te damon context was made for monitroing of a virtual address processes, and the process is terminated immediately, before the damon_call() invocation. In the case, the dyanmically allocated repeat_call_control is not deallocated and leaked. Fix the leak by deallocating the repeat_call_control under the damon_call() failure. This issue is discovered by sashiko [1].