timer_cancel - cancel a timer
#include <magenta/syscalls.h> mx_status_t mx_timer_cancel(mx_handle_t handle);
mx_timer_cancel() cancels a pending timer that was started with timer_set().
Upon success the pending timer is canceled and the MX_TIMER_SIGNALED signal is de-asserted. If a new pending timer is immediately needed rather than calling timer_cancel() first, call timer_set() with the new deadline.
mx_timer_cancel() returns MX_OK on success. In the event of failure, a negative error value is returned.
MX_ERR_BAD_HANDLE handle is not a valid handle.
MX_ERR_ACCESS_DENIED handle lacks the right MX_RIGHT_WRITE.
Calling this function before timer_set() has no effect.