lib/generic-radix-tree.c: add kmemleak annotations

lib/generic-radix-tree.c: add kmemleak annotations

Kmemleak is falsely reporting a leak of the slab allocation in
sctp_stream_init_ext():

  BUG: memory leak
  unreferenced object 0xffff8881114f5d80 (size 96):
   comm "syz-executor934", pid 7160, jiffies 4294993058 (age 31.950s)
   hex dump (first 32 bytes):
     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
   backtrace:
     [<00000000ce7a1326>] kmemleak_alloc_recursive  include/linux/kmemleak.h:55 [inline]
     [<00000000ce7a1326>] slab_post_alloc_hook mm/slab.h:439 [inline]
     [<00000000ce7a1326>] slab_alloc mm/slab.c:3326 [inline]
     [<00000000ce7a1326>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
     [<000000007abb7ac9>] kmalloc include/linux/slab.h:547 [inline]
     [<000000007abb7ac9>] kzalloc include/linux/slab.h:742 [inline]
     [<000000007abb7ac9>] sctp_stream_init_ext+0x2b/0xa0  net/sctp/stream.c:157
     [<0000000048ecb9c1>] sctp_sendmsg_to_asoc+0x946/0xa00  net/sctp/socket.c:1882
     [<000000004483ca2b>] sctp_sendmsg+0x2a8/0x990 net/sctp/socket.c:2102
     [...]

But it's freed later.  Kmemleak misses the allocation because its
pointer is stored in the generic radix tree sctp_stream::out, and the
generic radix tree uses raw pages which aren't tracked by kmemleak.

Fix this by adding the kmemleak hooks to the generic radix tree code.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Eric Biggers <[email protected]>
Reported-by: <[email protected]>
Reviewed-by: Marcelo Ricardo Leitner <[email protected]>
Acked-by: Neil Horman <[email protected]>
Reviewed-by: Catalin Marinas <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Vlad Yasevich <[email protected]>
Cc: Xin Long <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>