mm: vmstat: correct the comment above preempt_disable_nested()

The comment explaining why these parts use preempt_disable_nested() is in
__mod_zone_page_state(), not in __mod_node_page_state(), so we should see
__mod_zone_page_state(). Just correct it.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Qi Zheng <[e-mail]>
Acked-by: Vlastimil Babka <[e-mail]>
Acked-by: Harry Yoo <[e-mail]>
Cc: Liam Howlett <[e-mail]>
Cc: Lorenzo Stoakes <[e-mail]>
Cc: Michal Hocko <[e-mail]>
Cc: Mike Rapoport <[e-mail]>
Cc: Suren Baghdasaryan <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

mm/vmstat.c

···
 		delta >>= PAGE_SHIFT;
 	}
 
-	/* See __mod_node_page_state */
+	/* See __mod_zone_page_state() */
 	preempt_disable_nested();
 
 	x = delta + __this_cpu_read(*p);
···
 	s8 __percpu *p = pcp->vm_stat_diff + item;
 	s8 v, t;
 
-	/* See __mod_node_page_state */
+	/* See __mod_zone_page_state() */
 	preempt_disable_nested();
 
 	v = __this_cpu_inc_return(*p);
···
 
 	VM_WARN_ON_ONCE(vmstat_item_in_bytes(item));
 
-	/* See __mod_node_page_state */
+	/* See __mod_zone_page_state() */
 	preempt_disable_nested();
 
 	v = __this_cpu_inc_return(*p);
···
 	s8 __percpu *p = pcp->vm_stat_diff + item;
 	s8 v, t;
 
-	/* See __mod_node_page_state */
+	/* See __mod_zone_page_state() */
 	preempt_disable_nested();
 
 	v = __this_cpu_dec_return(*p);
···
 
 	VM_WARN_ON_ONCE(vmstat_item_in_bytes(item));
 
-	/* See __mod_node_page_state */
+	/* See __mod_zone_page_state() */
 	preempt_disable_nested();
 
 	v = __this_cpu_dec_return(*p);