staging: rtl8723bs: remove unused efuseValue from efuse_OneByteWrite()

staging: rtl8723bs: remove unused efuseValue from efuse_OneByteWrite()

The efuseValue is to store value from register EFUSE_CTRL, and set control
bits including address and write bit. This is no need for RTL8723BS, so
the consumer has been removed. Thus, remove these unused codes are safe.

Otherwiese, clang warns:

rtw_efuse.c:285:6: warning:
	 variable 'efuseValue' set but not used [-Wunused-but-set-variable]
  285 |         u32 efuseValue;
      |             ^

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/20240913002815.5149-3-pkshih@realtek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>