Clone volume with right size with SolidFire

It is possible to clone a volume with a size greater than
the source volume. When using the SolidFire driver, the volume size
was not passed in the call made to the SolidFire API when
cloning a volume.

It resulted in a cloned volume having the same size as the source
volume but the correct size in the Cinder database.

This changes makes sure the cloned volume has the correct size
by explicitly passing the requested size when calling
the SolidFire API and cloning the volume.

Fixes: bug #1219105
Change-Id: I5628c7fa922780d6b0601e2daa79310a61085edc
(cherry picked from commit 0a87ff988cd21586daeb6ed886e44aedaa49c320)
Merge "Clone volume with right size with SolidFire" into stable/grizzly
Merge remote-tracking branch 'upstream/stable/grizzly' into stable/grizzly