staging: r8188eu: Remove self assignment in get_rx_power_val_by_reg()

staging: r8188eu: Remove self assignment in get_rx_power_val_by_reg()

Clang warns:

drivers/staging/r8188eu/hal/rtl8188e_rf6052.c:344:13: warning:
explicitly assigning value of variable of type 'u32' (aka 'unsigned
int') to itself [-Wself-assign]
                        writeVal = writeVal;
                        ~~~~~~~~ ^ ~~~~~~~~
1 warning generated.

Remove this branch as it is useless.

Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20210805185807.3296077-3-nathan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>