drivers: virtio: Mark function virtballoon_migratepage() as static in virtio_balloon.c
drivers: virtio: Mark function virtballoon_migratepage() as static in virtio_balloon.c

Mark the function virtballoon_migratepage() as static in
virtio_balloon.c because it is not used outside this file.

This eliminates the following warning in virtio_balloon.c:
drivers/virtio/virtio_balloon.c:372:5: warning: no previous prototype for ‘virtballoon_migratepage’ [-Wmissing-prototypes]

Signed-off-by: Rashika Kheria <62a2cbd3422b0d621dafb7ceeff40187aeaed4ed@gmail.com>
Reviewed-by: Josh Triplett <c028c213ed5efcf30c3f4fc7361dbde0c893c5b7@joshtriplett.org>
Acked-by: Michael S. Tsirkin <255103e50249e3d658441816e0597170ebfc16ef@redhat.com>
Signed-off-by: Rusty Russell <df9728c9e5104131c08c7adb03af425394842596@rustcorp.com.au>

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