log.h: add head file <stdarg.h>
log.h: add head file <stdarg.h>


libcg was compiled failed in suse sp2 with libc-2.11.3:
"include/libcgroup/log.h:90: error: expected declaration specifiers
or '...' before 'va_list'"

 so add #include <stdarg.h>

Signed-off-by: Libo Chen <03ac321f4fc44d5558b43fe86a753e021008f32d@huawei.com>
Acked-by: Dhaval Giani <f48451d72a1ad74c777093928b661ad7099a85df@gmail.com>
Acked-by: Ivana Hutarova Varekova <2e3918a0a366ea7e658a2062ab582c898a7e1b1b@redhat.com>
Committer: Ivana Hutarova Varekova <2e3918a0a366ea7e658a2062ab582c898a7e1b1b@redhat.com>

rafalmiel/libcg,rafalmiel/libcg,rafalmiel/libcg,rafalmiel/libcg