staging: rtl8188eu: make const char array static

Make const char array 'fw_name' static. Clears a checkpatch warning
and reduces object file size by 17 bytes (gcc 9.3.1 x86_64).

WARNING: const array should probably be static const

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20200413175957.30165-4-straube.linux@gmail.com


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