media: c8sectpfe: Call of_node_put(i2c_bus) only once in c8sectpfe_probe()

An of_node_put(i2c_bus) call was immediately used after a pointer check
for an of_find_i2c_adapter_by_node() call in this function implementation.
Thus call such a function only once instead directly before the check.

This issue was transformed by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>