staging: pi433: fix memory leak with using debugfs_lookup()

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: staging: pi433: fix memory leak with using debugfs_lookup() When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. To make things simpler, just call debugfs_lookup_and_remove() instead which handles all of the logic at once. This requires saving off the root directory dentry to make creation of individual device subdirectories easier.

References

• https://git.kernel.org/stable/c/04f3cda40e9f6653ae15ed3fcf26ef2860f4df66
• https://git.kernel.org/stable/c/bb16f3102607b69e1a0233f4b73c6e337f86ef8d
• https://git.kernel.org/stable/c/2f36e789e540df6a9fbf471b3a2ba62a8b361586