gpu: nvgpu: remove unused list in priv_cmd_entry

list_head list in struct priv_cmd_entry is unused
and hence remove it

Jira NVGPU-13

Change-Id: I268998d84a43d2e22fdfae53a9c7795b20fcf93f
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/1462081
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: svccoveritychecker <svccoveritychecker@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

drivers/gpu/nvgpu/gk20a/mm_gk20a.h

@@ -153,7 +153,6 @@ struct priv_cmd_entry {
 	u64 gva;
 	u32 get;	/* start of entry in queue */
 	u32 size;	/* in words */
-	struct list_head list;	/* node for lists */
 };
 
 struct mapped_buffer_node {