Change serial_fd log from error to warn
Change serial_fd log from error to warn

This commit changes serial_FD log levels
from error to warn.

Signed-off-by: berciuliviu <319f2c7a587169a1a8e2b01a65430331726826d8@amazon.com>

firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker