mm: fix docbook comment for get_vaddr_frames()

get_vaddr_frames() has a comment that's *almost* a docbook comment; add
the missing star so that the tools will find it properly.
Signed-off-by: NJonathan Corbet <corbet@lwn.net>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/frame_vector.c

@@ -7,7 +7,7 @@
 #include <linux/pagemap.h>
 #include <linux/sched.h>
 
-/*
+/**
  * get_vaddr_frames() - map virtual addresses to pfns
  * @start:	starting user address
  * @nr_frames:	number of pages / pfns from start to map