staging: r8188eu: Fix some smatch errors in core/rtw_efuse.c

Smatch reports the following situations:

drivers/staging/rtl8188eu/core/rtw_efuse.c:589 rtw_efuse_map_write() error: buffer overflow 'newdata' 8 <= 8
drivers/staging/rtl8188eu/core/rtw_efuse.c:598 rtw_efuse_map_write() error: buffer overflow 'newdata' 8 <= 8
drivers/staging/rtl8188eu/core/rtw_efuse.c:681 rtw_BT_efuse_map_write() error: buffer overflow 'newdata' 8 <= 8
drivers/staging/rtl8188eu/core/rtw_efuse.c:690 rtw_BT_efuse_map_write() error: buffer overflow 'newdata' 8 <= 8

In these cases, it is possible to write beyond the end of an array.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>