DebugFS APIs are designed to return only the error pointers and not NULL
in the case of failure. So these return pointers are safe to be passed on
to the successive debugfs_create* APIs.

Therefore, let's just get rid of the checks.
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20220329154616.58902-1-manivannan.sadhasivam@linaro.orgSigned-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>