gitignore: Update gitignore to exclude autoconf/configure/make files

Also remove not relevant ignores.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
configure.ac: Fix xio Module.symvers location

Located at: /opt/xio/include

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
xnbd: Update log levels and remove unnecessary prints

Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Acked-by: Sagi Grimberg <sagig@mellanox.com>