Drivers: hv: balloon: Fix info request to show max page count

Balloon driver was only printing the size of the info blob and not the
actual content. This fixes it so that the info blob (max page count as
configured in Hyper-V) is printed out.

Signed-off-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>