include/inst: Expect arguments from opt_get_argv() in multiple lines

include/inst: Expect arguments from opt_get_argv() in multiple lines

The inst module expects `opt_get_argv()` to print all command line
arguments in one line, however the behavior of `opt_get_argv()` has
been changed to print arguments line-by-line.

This commit modifies the inst module so that it expects arguments to
be returned one per line by `opt_get_argv()`.