staging: vme: use image mutex for ioctl()
staging: vme: use image mutex for ioctl()

This implements more granular locking in vme_user_ioctl() by using separate
locks for each devfs device.

This also provides a synchronization between vme_user_read(), vme_user_write()
and vme_user_ioctl().

Signed-off-by: Dmitry Kalinkin <29815bb9c607b7ec4d5674c4d27228258621d840@gmail.com>
Cc: Martyn Welch <93f503ea252153691f7f4be57bef64a20c1117fb@ge.com>
Cc: Igor Alekseev <f6afc2a8bd1cc7c55abe68b48633cbbd93d243b8@itep.ru>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs