soc: qcom: glink_smem_native_xprt: Plug open command memory leak

When processing an open command, the smem native transport allocates some
memory to store the name of the channel, which gets passed up to the core.
The core makes a copy of the name, so the memory can be freed once the call
to the core returns.  The transport does not free this memory, leading to a
leak.

Free the memory allocated for the channel name after calling into the core
to plug the leak.

Change-Id: Ia789c06a7f7104c4e1f145996dc006d07d292752
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>