virSecurityDACSetOwnershipInternal: Fix WIN32 code

I must admit, I have no idea why we build such POSIX dependent
code as DAC driver for something such not POSIX as WIN32. Anyway,
the code which is supposed to set error is not doing that. The
proper way is to mimic what chown() does:

  On error, -1 is returned, and errno is set to indicate the error.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

src/security/security_dac.c

@@ -700,7 +700,8 @@ virSecurityDACSetOwnershipInternal(const virSecurityDACData *priv,
         }
 
 #ifdef WIN32
-        rc = ENOSYS;
+        rc = -1;
+        errno = ENOSYS;
 #else /* !WIN32 */
         rc = chown(path, uid, gid);
 #endif /* !WIN32 */