staging: rts5208: Remove negations

staging: rts5208: Remove negations

Previously return variable fake_para was being negated before return.
For simplification, fake_para can be changed to valid_para, which is
returned without negation (corresponding values swapped accordingly).
Further, the function names check_sd_current_prior and check_sd_speed_prior
can be changed to valid_sd_current_prior and valid_sd_speed_prior
respectively for greater clarity on the purpose of the functions.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>