drivers: rmnet: shs: Remove unecessary dereference

Remove double dereference to get segs_per_skb.
This should prevent a null dereference is node is invalid.

Change-Id: I6f199457088c9f33d69192dd24360b95718db54d
Acked-by: Raul Martinez <mraul@qti.qualcomm.com>
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>