staging: speakup: add braces around else statement

Add braces {} around else statement to conform to the Linux kernel
coding style. Issue found using checkpatch.

Signed-off-by: Santha Meena Ramamoorthy <santhameena13@gmail.com>
Acked-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>