staging: rtl8188eu: core: fix coding style issues

Fixing WARNING: Prefer using '"%s...", __func__' to using 'function_name'
in a string in rtw_ioctl_set.c

Signed-off-by: Arpitha Raghunandan <98.arpi@gmail.com>
Link: https://lore.kernel.org/r/20200715154623.78315-1-98.arpi@gmail.com


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