staging: gasket: core: simplify comments for static functions

Static functions don't need kernel doc formatting, can be simplified.
Reformat comments that can be single-line.  Remove extraneous text.
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>