linux(4): Prevent time_t overflows on i386.

As native i386 time_t is still 32-bit, check that the user-provided 64-bit
tv_sec value fits to the kernel time_t, return EOVERFLOW if not.

MFC after: 2 weeks

(cherry picked from commit 3dc2a06752b593acd1a76e784b169f3d60e81d00)