staging: vme_user: Replace "<<" with BIT macro

Replace the "<<" operator with BIT macro, in accordance to the
checkpatch.pl script and Linux kernel coding-style guidelines.
Signed-off-by: Abhirup Deb <abhirupdeb@linux.vnet.ibm.com>
Link: https://lore.kernel.org/r/ZBipKh/e2lK3YcQr@li-27defe4c-32e1-11b2-a85c-e202e9981075.ibm.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>