PM / Hibernate: Update some comments in core hibernate code

Some comments in the core hibernate code are outdated, some aren't
necessary any more and at least one of them is plain wrong.  Remove
those comments or update them.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

kernel/power/hibernate.c

@@ -248,12 +248,6 @@ static int create_image(int platform_mode)
 	if (error)
 		return error;
 
-	/* At this point, dpm_suspend_start() has been called, but *not*
-	 * dpm_suspend_noirq(). We *must* call dpm_suspend_noirq() now.
-	 * Otherwise, drivers for some devices (e.g. interrupt controllers)
-	 * become desynchronized with the actual state of the hardware
-	 * at resume time, and evil weirdness ensues.
-	 */
 	error = dpm_suspend_noirq(PMSG_FREEZE);
 	if (error) {
 		printk(KERN_ERR "PM: Some devices failed to power down, "
@@ -297,9 +291,6 @@ static int create_image(int platform_mode)
 
  Power_up:
 	syscore_resume();
-	/* NOTE:  dpm_resume_noirq() is just a resume() for devices
-	 * that suspended with irqs off ... no overall powerup.
-	 */
 
  Enable_irqs:
 	local_irq_enable();
@@ -416,24 +407,26 @@ static int resume_target_kernel(bool platform_mode)
 	if (error)
 		goto Enable_irqs;
 
-	/* We'll ignore saved state, but this gets preempt count (etc) right */
 	save_processor_state();
 	error = restore_highmem();
 	if (!error) {
 		error = swsusp_arch_resume();
 		/*
 		 * The code below is only ever reached in case of a failure.
-		 * Otherwise execution continues at place where
-		 * swsusp_arch_suspend() was called
+		 * Otherwise, execution continues at the place where
+		 * swsusp_arch_suspend() was called.
 		 */
 		BUG_ON(!error);
-		/* This call to restore_highmem() undos the previous one */
+		/*
+		 * This call to restore_highmem() reverts the changes made by
+		 * the previous one.
+		 */
 		restore_highmem();
 	}
 	/*
 	 * The only reason why swsusp_arch_resume() can fail is memory being
 	 * very tight, so we have to free it as soon as we can to avoid
-	 * subsequent failures
+	 * subsequent failures.
 	 */
 	swsusp_free();
 	restore_processor_state();