In the latest git commits of libilbc developers removed WebRtc_xxx typedefs.
This commit uses int types instead. It's safe to apply also for previous
versions since WebRtc_Word16 was always a typedef of int16_t and
WebRtc_UWord16 a typedef of uint16_t.
Reviewed-by: Timothy Gu <timothygu99@gmail.com>
Signed-off-by: Diego Biurrun <diego@biurrun.de>