wlan: Set FTM state to stopped during wlan_hdd_ftm_close

When wlan_ftm_stop is called from wlan_hdd_ftm_close, the FTM state is not
set to STOPPED which can lead to the FTM state being in older STARTED
state. In this scenario, if the wlan_hdd_ftm_close is called again,
wlan_ftm_stop is invoked again leading to WDA Stop to FW in already
stopped state.

Set the FTM State to STOPPPED after wlan_ftm_stop in wlan_hdd_ftm_close.

Change-Id: If6b2471f5737f0bed0025c322670e12c41836c51
CRs-Fixed: 2342273