Staging: sm750fb: Fix C99 Comments

Used C89 instead of C99 Comment and removed C99 comments performing prints only.
Problem found using checkpatch.pl
ERROR: do not use C99 // comments

Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>