[PATCH] libxc: avoid clobbering errno in xc_domain_pod_target()

[Jan Beulich]

do_memory_op() supplies return value and has errno set the usual way.
Don't overwrite errno with 1 (aka EPERM on at least Linux).

Signed-off-by: Jan Beulich <jbeul...@suse.com>
---
An alternative would be to let go of the DPRINTK() and leave errno and
err alone altogether. While the hypervisor side of the hypercall gives
the impression of being able to return positive values as of
637a283f17eb ("PoD: Allow pod_set_cache_target hypercall to be
preempted"), due to the use of "rc >= 0" there, afaict that's not
actually the case. IOW "err" can really only be 0 or -1 here.

--- a/tools/libs/ctrl/xc_domain.c
+++ b/tools/libs/ctrl/xc_domain.c
@@ -1231,10 +1231,11 @@ static int xc_domain_pod_target(xc_inter
 
     if ( err < 0 )
     {
+        err = errno;
         DPRINTF("Failed %s_pod_target dom %d\n",
                 (op==XENMEM_set_pod_target)?"set":"get",
                 domid);
-        errno = -err;
+        errno = err;
         err = -1;
     }
     else