drivers: staging: vme: convert to octal notation for permission bits

Ran checkpatch.pl -f vme_pio2_core.c
Fixed: WARNING: Symbolic permissions are not preferred. Consider using
octal permissions (0444)

Signed-off-by: Andrew Kanner <andrew.kanner@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>