Documentation: core-api/cpuhotplug: Fix missing prefix

Add the missing cpuhp_ prefix in cpuhp_remove_multi_state().

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240927185229.2362599-1-lucas.demarchi@intel.com

Author: Lucas De Marchi

Documentation/core-api/cpu_hotplug.rst

@@ -616,7 +616,7 @@ ONLINE section for notifications on online and offline operation::
    ....
    cpuhp_remove_instance(state, &inst2->node);
    ....
-   remove_multi_state(state);
+   cpuhp_remove_multi_state(state);
 
 
 Testing of hotplug states