The proberi assembler instruction checks the read/write access rights
for the page of a given address and shall return a value of 1 if the
test succeeds and a value of 0 on failure in the target register.

But when run in linux-user mode, qemu currently simply returns the
return code of page_check_range() which returns 0 on success and -1 on
failure, which is the opposite of what proberi should return.

Fix it by checking the return code of page_check_range() and return the
expected return value.

The easiest way to reproduce the issue is by running
"/lib/ld.so.1 --version" in a chroot which fails without this patch.
At startup of ld.so the __canonicalize_funcptr_for_compare() function is
used to resolve the function address out of a function descriptor, which
fails because proberi (due to the wrong return code) seems to indicate
that the given address isn't accessible.

Signed-off-by: Helge Deller <deller@gmx.de>