trace: ipc_logging: Fix memory leak of "struct dfunc_info"

Memory allocated during context created is not getting freed
while context destroyed.

Free the "struct dfunc_info" memory while context destroy.

CRs-Fixed: 2319209
Change-Id: I472c09e147d5bc109745176601b329616d5be111
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>