remoteproc: Change rproc_shutdown() to return a status

The rproc_shutdown() function is currently not returning any
error code, and any failures within rproc_stop() are not passed
back to the users. Change the signature to return a success value
back to the callers.

The remoteproc sysfs and cdev interfaces are also updated to
return back this status to userspace.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220213201246.25952-2-s-anna@ti.com
diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c
index abf0cd0..51a04bc 100644
--- a/drivers/remoteproc/remoteproc_sysfs.c
+++ b/drivers/remoteproc/remoteproc_sysfs.c
@@ -206,7 +206,7 @@ static ssize_t state_store(struct device *dev,
 		    rproc->state != RPROC_ATTACHED)
 			return -EINVAL;
 
-		rproc_shutdown(rproc);
+		ret = rproc_shutdown(rproc);
 	} else if (sysfs_streq(buf, "detach")) {
 		if (rproc->state != RPROC_ATTACHED)
 			return -EINVAL;