tools/libxendevicemodel: Strip __XEN_TOOLS__ header guard

This is inappropriate for the header file of a standalone library with stable
API and ABI.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Ian Jackson <iwj@xenproject.org>
Release-Acked-by: Ian Jackson <iwj@xenproject.org>

tools/include/xendevicemodel.h

@@ -17,8 +17,6 @@
 #ifndef XENDEVICEMODEL_H
 #define XENDEVICEMODEL_H
 
-#ifdef __XEN_TOOLS__
-
 #include <stdint.h>
 
 #include <xen/xen.h>
@@ -377,8 +375,6 @@ int xendevicemodel_nr_vcpus(
  */
 int xendevicemodel_restrict(xendevicemodel_handle *dmod, domid_t domid);
 
-#endif /* __XEN_TOOLS__ */
-
 #endif /* XENDEVICEMODEL_H */
 
 /*