staging: fbtft: fbtft-io.c: remove extra parentheses around function arguments

Removes extra parentheses around function arguments. Issue
detected and resolved using the following coccinelle script:

@@
expression e;
identifier f;
@@

f(...,
-(
e
-)
,...)

Signed-off-by: Aya Mahfouz <mahfouz.saif.elyazal@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>