The fourth argument should be unsigned.  Also add missing include
so that the function prototype is defined in xattr_id.c

This fixes a couple of sparse warnings.
Signed-off-by: NPhillip Lougher <phillip@lougher.demon.co.uk>

Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NPhillip Lougher <phillip@lougher.demon.co.uk>

Sparse detected that unsigned pointer was being passed as int pointer.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
[fixed up to deal with code refactoring]
Signed-off-by: NPhillip Lougher <phillip@lougher.demon.co.uk>

Signed-off-by: NPhillip Lougher <phillip@lougher.demon.co.uk>