apply.c::find_name_traditional(): do not initialize len to the line's length

apply.c::find_name_traditional(): do not initialize len to the line's length

The variable len is set to

    len = strchrnul(line, '\n') - line;

unconditionally 9 lines later, hence we can remove the call to strlen.

Signed-off-by: Stefan Beller <redacted>
Signed-off-by: Junio C Hamano <redacted>