[PATCH for-4.14] tools: fix error path of xendevicemodel_open()

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

c/s 6902cb00e03 "tools/libxendevicemodel: extract functions and add a compat
layer" introduced calls to both xencall_open() and osdep_xendevicemodel_open()
but failed to fix up the error path.

c/s f68c7c618a3 "libs/devicemodel: free xencall handle in error path in
_open()" fixed up the xencall_open() aspect of the error path (missing the
osdep_xendevicemodel_open() aspect), but positioned the xencall_close()
incorrectly, creating the same pattern proved to be problematic by c/s
30a72f02870 "tools: fix error path of xenhypfs_open()".

Reposition xtl_logger_destroy(), and introduce the missing
osdep_xendevicemodel_close().

Fixes: 6902cb00e03 ("tools/libxendevicemodel: extract functions and add a 
compat layer")
Fixes: f68c7c618a3 ("libs/devicemodel: free xencall handle in error path in 
_open()")
Backport: 4.9+
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Ian Jackson <Ian.Jackson@xxxxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>
CC: Juergen Gross <jgross@xxxxxxxx>
CC: Paul Durrant <paul@xxxxxxx>

RFC - this is still broken.

Failure to create the logger will still hit the NULL deference, in all of the
stable libs, not just devicemodel.

Also, unless I'd triple checked the history, I was about to reintroduce the
deadlock from c/s 9976f3874d4, because it totally counterintuitive wrong to
expect setup and teardown in opposite orders.
---
 tools/libs/devicemodel/core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/libs/devicemodel/core.c b/tools/libs/devicemodel/core.c
index db501d9e80..4d4063956d 100644
--- a/tools/libs/devicemodel/core.c
+++ b/tools/libs/devicemodel/core.c
@@ -67,9 +67,10 @@ xendevicemodel_handle *xendevicemodel_open(xentoollog_logger 
*logger,
     return dmod;
 
 err:
-    xtl_logger_destroy(dmod->logger_tofree);
+    osdep_xendevicemodel_close(dmod);
     xentoolcore__deregister_active_handle(&dmod->tc_ah);
     xencall_close(dmod->xcall);
+    xtl_logger_destroy(dmod->logger_tofree);
     free(dmod);
     return NULL;
 }
-- 
2.11.0