main: Use type int for getopt return value
main: Use type int for getopt return value

The signedness of char differs from platform to platform; to portably
compare the return value from getopt_long to -1, we have to store it
in an int.

This fixes an infinite loop on powerpc where char is an unsigned
char.

RaphaelRochet/easystroke,thjaeger/easystroke,thjaeger/easystroke,RaphaelRochet/easystroke