tools: zynqmp_psu_init_minimize.sh: fix return lines coding style
Remove unneeded parenthess around return value. E.g.:
return (0); -> return 0;
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>