bus: mhi: replace snprintf with sysfs_emit

Fix following coccicheck warning:
./drivers/bus/mhi/host/init.c:89:8-16: WARNING: use scnprintf or sprintf

Use sysfs_emit and sysfs_emit_at instead of snprintf.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Link: https://lore.kernel.org/r/20220426125902.681258-1-wanjiabing@vivo.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>