firmware-utils: mkhilinkfw: fix compiler warnings/errors
mkhilinkfw.c:45:9: error: comparison of integer expressions of different signedness: ‘off_t’ {aka ‘long int’} and ‘long unsigned int’ [-Werror=sign-compare]
mkhilinkfw.c:45:16: error: operand of ?: changes signedness from ‘off_t’ {aka ‘long int’} to ‘long unsigned int’ due to unsignedness of other operand [-Werror=sign-compare]
mkhilinkfw.c:45:9: error: comparison of integer expressions of different signedness: ‘off_t’ {aka ‘long int’} and ‘long unsigned int’ [-Werror=sign-compare]
mkhilinkfw.c:45:16: error: operand of ?: changes signedness from ‘off_t’ {aka ‘long int’} to ‘long unsigned int’ due to unsignedness of other operand [-Werror=sign-compare]
mkhilinkfw.c:281:9: error: ignoring return value of ‘write’, declared with attribute warn_unused_result [-Werror=unused-result]
Signed-off-by: Petr Štetiar <ynezz@true.cz>