rmnet: shs: Fix KW reported issues

Suspicious dereference of pointer 'ptr' before NULL check at line 673
rmnet_shs_flush_core()
Suspicious dereference of pointer 'ptr' before NULL check at line 874
rmnet_shs_flush_lock_table()
'hash2stamp' might be used uninitialized in this function.
rmnet_shs_flush_node()
Pointer 'hnode' checked for NULL at line 334 will be dereferenced at line 333.
rmnet_shs_wq_get_new_hstat_node()
Pointer 'ep' checked for NULL at line 418 will be dereferenced at line 416.
rmnet_shs_wq_update_hstat_rps_msk()
Pointer 'ep' checked for NULL at line 779 will be dereferenced at line 778.
rmnet_shs_wq_get_dev_rps_msk()
Pointer 'ep' checked for NULL at line 926 will be dereferenced at line 925.
rmnet_shs_wq_find_cpu_and_move_flows()
Pointer 'ep' checked for NULL at line 1075 will be dereferenced at line 1074.
rmnet_shs_wq_refresh_new_flow_list()
Pointer 'ep' checked for NULL at line 1099 will be dereferenced at line 1098.
rmnet_shs_wq_get_lpwr_cpu_new_flow()
Pointer 'ep' checked for NULL at line 1148 will be dereferenced at line 1147.
rmnet_shs_wq_get_perf_cpu_new_flow()
Pointer 'ep' checked for NULL at line 1276 will be dereferenced at line 1275.
rmnet_shs_wq_reset_ep_active()
Pointer 'ep' checked for NULL at line 1290 will be dereferenced at line 1289.
rmnet_shs_wq_set_ep_active()
Pointer 'ep' checked for NULL at line 1305 will be dereferenced at line 1303.
rmnet_shs_wq_refresh_ep_masks()
Pointer 'hnode' checked for NULL at line 1349 will be dereferenced at line 1348.
rmnet_shs_wq_update_stats()
Suspicious dereference of pointer 'ptr' before NULL check at line 1209
rmnet_shs_wq_cleanup_hash_tbl()
Suspicious dereference of pointer 'ptr' before NULL check at line 1390
rmnet_shs_wq_clean_ep_tbl()

Change-Id: Ic978ddcd246efaaae045b890d15c1e7c3bb6bca8
Signed-off-by: Sharath Chandra Vurukala <sharathv@codeaurora.org>