add: use struct argv_array in run_add_interactive()
add: use struct argv_array in run_add_interactive()

run_add_interactive() in builtin/add.c manually computes array bounds
and allocates a static args array to build the add--interactive command
line, which is error-prone. Use the argv-array helper functions instead.

Signed-off-by: Fabian Ruch <82296eb15e8045a1d569dd3417ad2c54f4c3eb07@gmail.com>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git