mm/mempolicy.c: fix indentation of the comments of do_migrate_pages

Currently, do_migrate_pages() have very long comment and this is not
indent properly.  I often misunderstand it is function starting commnents
and confused it.

this patch fixes it.

note: this patch doesn't break 80 column rule. I guess original
      author intended this indentaion, but an accident corrupted it.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/mempolicy.c

@@ -888,7 +888,7 @@ int do_migrate_pages(struct mm_struct *mm,
 	if (err)
 		goto out;
 
-/*
+	/*
 	 * Find a 'source' bit set in 'tmp' whose corresponding 'dest'
 	 * bit in 'to' is not also set in 'tmp'.  Clear the found 'source'
 	 * bit in 'tmp', and return that <source, dest> pair for migration.