compat: backport lib/scatterlist.c from 0db9299f

compat: backport lib/scatterlist.c from 0db9299f

Backport the lib/scatterlist.c addition, this required
just removing the kmemleak stuff as that is not available
on older kernels.

mcgrof@frijol ~/linux-next (git::master)$ git describe --contains 0db9299f
v2.6.25-rc1~1173^2~2

commit 0db9299f48ebd4a860d6ad4e1d36ac50671d48e7
Author: Jens Axboe <jens.axboe@oracle.com>
Date:   Fri Nov 30 09:16:50 2007 +0100

    SG: Move functions to lib/scatterlist.c and add sg chaining allocator helpers

    Manually doing chained sg lists is not trivial, so add some helpers
    to make sure that drivers get it right.

    Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
1   2.6.24              [  OK  ]
2   2.6.25              [  OK  ]
3   2.6.26              [  OK  ]
4   2.6.27              [  OK  ]
5   2.6.28              [  OK  ]
6   2.6.29              [  OK  ]
7   2.6.30              [  OK  ]
8   2.6.31              [  OK  ]
9   2.6.32              [  OK  ]
10  2.6.33              [  OK  ]
11  2.6.34              [  OK  ]
12  2.6.35              [  OK  ]
13  2.6.36              [  OK  ]
14  2.6.37              [  OK  ]
15  2.6.38              [  OK  ]
16  2.6.39              [  OK  ]
17  3.0.65              [  OK  ]
18  3.1.10              [  OK  ]
19  3.2.38              [  OK  ]
20  3.3.8               [  OK  ]
21  3.4.32              [  OK  ]
22  3.5.7               [  OK  ]
23  3.6.11              [  OK  ]
24  3.7.9               [  OK  ]
25  3.8.0               [  OK  ]
26  3.9-rc1             [  OK  ]

Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>