cppcheck: Suppress same-value-in-ternary branches warning

TIMER_INTERVAL is the minimum of two separately defined intervals which
happen to have the same value at present.  This results in an expression
which has the same value in both branches of a ternary operator, which
cppcheck warngs about.  This is logically sound in this case, so suppress
the error (we appear to already have a similar suppression for clang-tidy).

Also add an unmatchedSuppression suppression, since only some cppcheck
versions complain about this instance.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

passt.c

@@ -305,6 +305,7 @@ int main(int argc, char **argv)
 
 loop:
 	/* NOLINTNEXTLINE(bugprone-branch-clone): intervals can be the same */
+	/* cppcheck-suppress [duplicateValueTernary, unmatchedSuppression] */
 	nfds = epoll_wait(c.epollfd, events, EPOLL_EVENTS, TIMER_INTERVAL);
 	if (nfds == -1 && errno != EINTR) {
 		perror("epoll_wait");