mm: fix memory.c incorrect kernel-doc

Fix mm/memory.c incorrect kernel-doc function notation:

  Warning(mm/memory.c:3718): Cannot understand  * @access_remote_vm - access another process' address space
   on line 3718 - I thought it was a doc line

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>