staging: r8188eu: binstallGrpkey is set to _FAIL

The variable binstallGrpkey is set to _FAIL which is defined as 0.
Use false to set the variable to get rid of another use of _FAIL.

Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20221111083733.3144-5-straube.linux@gmail.com


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