PTR_ERR should be called before its argument is cleared.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression e,e1;
constant c;
@@

*e = c
... when != e = e1
    when != &e
    when != true IS_ERR(e)
*PTR_ERR(e)
// </smpl>
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Reported-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>