cpu/hotplug: Fix notify_cpu_starting() reference in bringup_wait_for_ap()

bringup_wait_for_ap() comment references cpu_notify_starting(), but the 
function is actually called notify_cpu_starting(). Fix that.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/nycvar.YFH.7.76.1905282128100.1962@cbobk.fhfr.pm

kernel/cpu.c

@@ -522,7 +522,7 @@ static int bringup_wait_for_ap(unsigned int cpu)
 	/*
 	 * SMT soft disabling on X86 requires to bring the CPU out of the
 	 * BIOS 'wait for SIPI' state in order to set the CR4.MCE bit.  The
-	 * CPU marked itself as booted_once in cpu_notify_starting() so the
+	 * CPU marked itself as booted_once in notify_cpu_starting() so the
 	 * cpu_smt_allowed() check will now return false if this is not the
 	 * primary sibling.
 	 */