coresight: release reference taken by 'bus_find_device()'

BugLink: https://bugs.launchpad.net/bugs/1826212

[ Upstream commit f2dfab35 ]

The reference count taken by function bus_find_device() needs
to be released if a child device is found, something this patch
is adding.
Reported-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/hwtracing/coresight/coresight.c

@@ -573,6 +573,8 @@ static void coresight_fixup_device_conns(struct coresight_device *csdev)
 
 		if (dev) {
 			conn->child_dev = to_coresight_device(dev);
+			/* and put reference from 'bus_find_device()' */
+			put_device(dev);
 		} else {
 			csdev->orphan = true;
 			conn->child_dev = NULL;