eal: fix access to huge page with high address

eal: fix access to huge page with high address

The returned value of lseek is a virtual address
which can be different from the offset.
Indeed, if the return address has a 64-bit canonical form,
the 16 higher bits are all 1 if bit 47 is 1.

So the check was wrong. It is better to test against an error value.

Signed-off-by: Thomas Monjalon <thomas.monjalon@6wind.com>
Acked-by: Damien Millescamps <damien.millescamps@6wind.com>