staging: gpib: Fix uapi include header guard name

When gpib_user.h was renamed to gpio.h the include guard name was
not changed accordingly.

Change the include guard name to correspond with the file name
and cleanup the comments after the #endif.

Fixes: c7184cbf ("staging: gpib: Rename common include file")
Signed-off-by: Dave Penkler <dpenkler@gmail.com>
Link: https://lore.kernel.org/r/20250509113014.9105-1-dpenkler@gmail.com


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