Two fixes for issues detected by cppcheck 2.22.0.
The first is a real simplification: a !partial_send guard in
tcp_data_from_tap() is always true when reached, because partial_send
causes an early return above it, so the condition is dropped.
The second is a false positive: cppcheck flags buf[n - 1] as a
potential negative index in passt-repair.c, not tracking that n < 0
and n < sizeof(*ev) are both handled before that point. The warning
is suppressed with an annotation.
Signed-off-by: Laurent Vivier