When idr_find() returns NULL to intent, no error return code of
qcom_glink_rx_data() is assigned.
To fix this bug, ret is assigned with -ENOENT in this case.

Fixes: 64f95f87 ("rpmsg: glink: Use the local intents when receiving data")
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Link: https://lore.kernel.org/r/20210306133624.17237-1-baijiaju1990@gmail.comSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>