staging: sm750fb: Replace multiple spaces with tabs when it suits

Replace multiple spaces before some comments with one tab. Aligning the
comment with the function below it.
Signed-off-by: NGabriela Bittencourt <gabrielabittencourt00@gmail.com>
Link: https://lore.kernel.org/r/20191029232207.4113-3-gabrielabittencourt00@gmail.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>