:securemsm-kernel: Fixed multiple listener registration on same fd

Added check to prevent more than one listener registration
on a fd. This could lead to potential vulnerabilities of use
after free while unregistering the listener.

Change-Id: Ia2973853943b5619bcf2047629b9c193f6a8c5cf
Signed-off-by: Pawan Rai <quic_pawarai@quicinc.com>
Signed-off-by: Ravi Kumar Bokka <rbokka@qti.qualcomm.com>
Signed-off-by: pkanojia <quic_pkanojia@quicinc.com>