drm: remove dev->vma_count

This is just used for a debugfs file, and we can easily reconstruct
this number by just walking the list twice. Which isn't really bad for
a debugfs file anyway.

So let's rip this out.

There's the other issue that the dev->vmalist itself is a bit useless,
since that can be reconstructed with all the memory mapping
information from proc. But remove that is a different topic entirely.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_info.c b/drivers/gpu/drm/drm_info.c
index 31da45c..7473035 100644
--- a/drivers/gpu/drm/drm_info.c
+++ b/drivers/gpu/drm/drm_info.c
@@ -234,14 +234,18 @@
 	struct drm_device *dev = node->minor->dev;
 	struct drm_vma_entry *pt;
 	struct vm_area_struct *vma;
+	unsigned long vma_count = 0;
 #if defined(__i386__)
 	unsigned int pgprot;
 #endif
 
 	mutex_lock(&dev->struct_mutex);
-	seq_printf(m, "vma use count: %d, high_memory = %pK, 0x%pK\n",
-		   atomic_read(&dev->vma_count),
-		   high_memory, (void *)(unsigned long)virt_to_phys(high_memory));
+	list_for_each_entry(pt, &dev->vmalist, head)
+		vma_count++;
+
+	seq_printf(m, "vma use count: %lu, high_memory = %pK, 0x%pK\n",
+		   vma_count, high_memory,
+		   (void *)(unsigned long)virt_to_phys(high_memory));
 
 	list_for_each_entry(pt, &dev->vmalist, head) {
 		vma = pt->vma;