drm/mm: Remove redundant assignment in drm_mm_reserve_node

In Pete Goodliffe words, "You can improve a system by adding new code. You
can also improve a system by removing code" - In this case, commit
"202b52b7" added new code to initialize end of the node. So, there
is no need for duplicated initialization, and this patch simply removes it.
Signed-off-by: Akeem G Abodunrin <akeem.g.abodunrin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200309151156.25040-1-akeem.g.abodunrin@intel.com

drivers/gpu/drm/drm_mm.c

@@ -405,10 +405,10 @@ next_hole(struct drm_mm *mm,
  */
 int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node)
 {
-	u64 end = node->start + node->size;
 	struct drm_mm_node *hole;
 	u64 hole_start, hole_end;
 	u64 adj_start, adj_end;
+	u64 end;
 
 	end = node->start + node->size;
 	if (unlikely(end <= node->start))