powerpc/pseries/cpuhp: remove obsolete comment from pseries_cpu_die

This comment likely refers to the obsolete DLPAR workflow where some
resource state transitions were driven more directly from user space
utilities, but it also seems to contradict itself: "Change isolate state to
Isolate [...]" is at odds with the preceding sentences, and it does not
relate at all to the code that follows.

Remove it to prevent confusion.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210927201933.76786-5-nathanl@linux.ibm.com

arch/powerpc/platforms/pseries/hotplug-cpu.c

@@ -137,11 +137,6 @@ static void pseries_cpu_die(unsigned int cpu)
 			cpu, pcpu);
 	}
 
-	/* Isolation and deallocation are definitely done by
-	 * drslot_chrp_cpu.  If they were not they would be
-	 * done here.  Change isolate state to Isolate and
-	 * change allocation-state to Unusable.
-	 */
 	paca_ptrs[cpu]->cpu_start = 0;
 }