Add missing trace call to oslib-posix.c:qemu_vmalloc()

Acked-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

oslib-posix.c

@@ -79,7 +79,10 @@ void *qemu_memalign(size_t alignment, size_t size)
 /* alloc shared memory pages */
 void *qemu_vmalloc(size_t size)
 {
-    return qemu_memalign(getpagesize(), size);
+    void *ptr;
+    ptr = qemu_memalign(getpagesize(), size);
+    trace_qemu_vmalloc(size, ptr);
+    return ptr;
 }
 
 void qemu_vfree(void *ptr)