livepatch: Improve error handling in klp_disable_func()

In case of func->state or func->old_addr not having expected values,
we'd rather bail out immediately from klp_disable_func().

This can't really happen with the current codebase, but fix this
anyway in the sake of robustness.

[[email protected]: reworded the changelog a bit]
Signed-off-by: Minfei Huang <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Jiri Kosina <[email protected]>
1 file changed