dump_pids: fix error: format specifies type 'long' but the argument has type 'int64_t' (aka 'long long') [-Werror,-Wformat]

gcc -DHAVE_CONFIG_H -I. -I..     -g -O2 -Wall -Werror --std=gnu99 -D_GNU_SOURCE -Wpointer-arith -Wcast-align -Wcast-qual -Wstrict-prototypes -Wshadow -Waggregate-return -Wmissing-prototypes -Wnested-externs -Wsign-compare -DDVBPSI_DIST -MT dump_pids-dump_pids.o -MD -MP -MF .deps/dump_pids-dump_pids.Tpo -c -o dump_pids-dump_pids.o `test -f 'dump_pids.c' || echo './'`dump_pids.c
dump_pids.c:56:54: error: format specifies type 'long' but the argument has type 'int64_t' (aka 'long long') [-Werror,-Wformat]
        printf("packet %ld, pid %u (0x%x), cc %d\n", n, pid, pid, cc );
                       ~~~                           ^
                       %lld
1 error generated.
make[3]: *** [dump_pids-dump_pids.o] Error 1
make[2]: *** [all-recursive] Error 1
make[1]: *** [all-recursive] Error 1
make: *** [all] Error 2

Signed-off-by: Michael Ira Krufky <mkrufky@linuxtv.org>