HID: intel-ish-hid: fix wrong error handling in ishtp_cl_alloc_tx_ring()

When allocating tx ring buffers failed, should free tx buffers, not rx buffers.

Signed-off-by: Zhang Lixu <lixu.zhang@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>