WIFIHAL: Fix use-after-free issue while freeing monitor socket list

During cleanup of monitor socket list, entries are freed
with out being deleted from the list. This results in
accessing memory which was already freed.
Hence deleting the entry before freeing it, so that
list would have only valid entries.

Bug: 133773150
Test: Manual Test
CRs-Fixed: 2463143
Change-Id: Ic746c7527958f238c77ddd4fd6d98cb8abab67bb
Signed-off-by: Vinay Gannevaram <quic_vganneva@quicinc.com>