[libvirt] [PATCH 3/4] build: fix virthread build on mingw

[Eric Blake]

Our recent conversion to make VIR_ALLOC report oom wasn't
tested on mingw:

In file included from ../../src/util/virthread.c:29:0:
../../src/util/virthreadwin32.c: In function 'virCondWait':
../../src/util/virthreadwin32.c:166:81: error: 'VIR_FROM_THIS' undeclared (first use in this function)
     if (VIR_REALLOC_N(c->waiters, c->nwaiters + 1) < 0) {
                                                                                 ^

* src/util/virthreadwin32.c (VIR_FROM_THIS): Define.

Signed-off-by: Eric Blake <eblake at redhat.com>
---
 src/util/virthreadwin32.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/util/virthreadwin32.c b/src/util/virthreadwin32.c
index 8928414..5d6277f 100644
--- a/src/util/virthreadwin32.c
+++ b/src/util/virthreadwin32.c
@@ -25,6 +25,8 @@

 #include "viralloc.h"

+#define VIR_FROM_THIS VIR_FROM_NONE
+
 struct virThreadLocalData {
     DWORD key;
     virThreadLocalCleanup cleanup;
-- 
1.8.3.1