staging: r8188eu: use kernel functions for timeout handling

Use the kernel functions to set a timeout and to check if it's expired.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20220413193654.258507-6-martin@kaiser.cx


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