[WCNCR00166796] sniffer: fix coding error

[Description]
Fix coding error
Should enclose sniffer mode code with fgIsEnableMon

Change-Id: Ia9f57a32fe3adc7fcc6d09f3e9e444fcb6bc6aee
CR-Id: WCNCR00166796
Feature: sniffer
Signed-off-by: guo-jie.wang <guo-jie.wang@mediatek.com>
2 files changed