staging: r8188eu: remove _linked_rx_signal_strength_display()

staging: r8188eu: remove _linked_rx_signal_strength_display()

The function _linked_rx_signal_strength_display() only sets two local
variables that are not used after setting. Remove the function and
remove resulting dead code.

The HW_DEF_RA_INFO_DUMP case in GetHalDefVar8188EUsb() does not set
the passed variable. It just calls check_fwstate() which does nothing
than return true or false. So it is safe to remove this call to
GetHalDefVar8188EUsb().

The HAL_DEF_UNDERCORATEDSMOOTHEDPWDB case in GetHalDefVar8188EUsb()
does nothing than set the passed variable and it is safe to remove
this call to GetHalDefVar8188EUsb() as well.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20220225174827.15927-1-straube.linux@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>