[DTV00857290][DTV][Coverity Scanned Code Defect]

[Description]
Fix coverity defects under nic/nic_rx.c

Fix Unchecked return value.
 - Cid#361464 in line 233.

Fix Logically dead code.
 - Cid#69863 in line 901.

Fix Dereference after null check.
 - Cid#74440 in line 3261.
 Add null check in mgmt/p2p_rlm.c.

Change-Id: I40c4627027a9f4067ec41f1a39f164d852ab9713
Signed-off-by: Alice Ou <alice.ou@mediatek.com>
CR-Id: DTV00857290
(cherry picked from commit ee14dbcaeb90fa93a9ffbbac39824daf0ea5c28a)
(cherry picked from commit 23f82558cb226b23f84f3488c31b38cdc9d99810)
(cherry picked from commit 486fe0770035cc05487427139bb46901fc084b19)
2 files changed