[patch] drm/i915: use _safe version of list_for_each

[Dan Carpenter]

We sometimes call i915_vma_unbind() inside the loop and that can free
the vma.

Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
---
Static checker stuff.  Untested.

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c 
b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 9b3b5f8..5249735 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -524,7 +524,7 @@ i915_gem_execbuffer_reserve(struct intel_ring_buffer *ring,
                            bool *need_relocs)
 {
        struct drm_i915_gem_object *obj;
-       struct i915_vma *vma;
+       struct i915_vma *vma, *n;
        struct list_head ordered_vmas;
        bool has_fenced_gpu_access = INTEL_INFO(ring->dev)->gen < 4;
        int retry;
@@ -572,7 +572,7 @@ i915_gem_execbuffer_reserve(struct intel_ring_buffer *ring,
                int ret = 0;

                /* Unbind any ill-fitting objects or pin. */
-               list_for_each_entry(vma, vmas, exec_list) {
+               list_for_each_entry_safe(vma, n, vmas, exec_list) {
                        struct drm_i915_gem_exec_object2 *entry = 
vma->exec_entry;
                        bool need_fence, need_mappable;