libxl: Change claim_mode from bool to int.

libxl: Change claim_mode from bool to int.

During the review it was noticed that it would be better if internally
the claim_mode was held as an 'int' instead of a 'bool'. The reason
is that during the startup of xl, one has call the libxl_defbool_setdefault.
otherwise any usage of claim_mode would result in assert break.

The assert is due to the fact that using defbool without any set
values (either true of false) will cause it hit an assertion.

If we use an 'int' we don't have to worry about it and by default
the value of zero will suffice for checks whether the claim is
enabled or disabled.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ian Campbell <Ian.Campbell@citrix.com>