mm/damon/sysfs: dealloc repeat_call_control if damon_call() fails

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].