Input: zinitix - fix return type of zinitix_init_touch()

zinitix_init_touch() returns error code or 0 for success and therefore
return type must be int, not bool.

Fixes: 26822652 ("Input: add zinitix touchscreen driver")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Link: https://lore.kernel.org/r/YC8z2bXc3Oy8pABa@google.com


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>