[DTV00925143] misc: fix coverity issue

[Description]
Fix CID
4181347: Dereference before null check, nicCmdEventGetTxPwrTbl()
4181351: Resource leak, procGetTxpwrTblRead()
4181352: Dead default in switch, print_txpwr_tbl()
4181359: Logically dead code, priv_driver_coex_ctrl()

Change-Id: I467a049331bc0d1ee7fbf6d4649fc958e5099fbc
CR-Id: DTV00925143
Signed-off-by: guo-jie.wang <guo-jie.wang@mediatek.com>
Feature: misc
Reviewed-on: http://gerrit.mediatek.inc:8080/1300818
CheckPatch: Check Patch <srv_checkpatch@mediatek.com>
Reviewed-by: George Kuo <george.kuo@mediatek.com>
Reviewed-by: Sarick Jiang <sarick.jiang@mediatek.com>
Build: srv_neptune_adm <srv_neptune_adm@mediatek.com>
Test: srv_neptune_adm <srv_neptune_adm@mediatek.com>
2 files changed