staging: r8188eu: clarify that bb_reg_dump uses only path a

The path variable is always 0 in bb_reg_dump. Remove the path variable
and replace the constant 0 with RF_PATH_A to make it clearer that path
a is used.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20220212161737.381841-6-martin@kaiser.cx


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