staging: r8188eu: make numNQ a u8

The numNQ variable in _InitQueueReservedPage is defined as u32. It is
either set to 0 or to 0x1C. Change its type to u8 and remove the code that
casts the u32 value to u8.

Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20220808201405.68966-3-martin@kaiser.cx


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