Include next link when default limit is reached

Include next link when default limit is reached

The /volumes and /volumes/details APIs support pagination and a
"next" link should be included when more data is available. When
the default "osapi_max" limit is reached then the "next" link is
not included in the API reply. In this case, the caller cannot
determine if there are any more volumes and has no marker value
such that they can retrieve the rest of the volumes.

The fix for this is to include the "next" link when the number of
volumes being returned is the maximum limit, even if the "limit"
parameter is not supplied.

Change-Id: I2f04192e67f80232b4019194f718625dbaf78fa6
Closes-bug: 1288429