Increase timeout period for clone volume.

Current timeout value for clone volume in the
SolidFire driver is 20 seconds, this is fine
in many cases however there seems to be a
number of customers doing clones of
volumes >= 400G.

A populated 400G volume is taking upwards of
35 seconds to clone in some cases resulting in failure.

There's no reason not to bump this timeout value up
significantly to a worst case scenario (ie multi-terrabyte volume).

Fixes bug: 1202007

Change-Id: I98c399f5d647e14f031018f7fc1cc43bb0d94c84

cinder/volume/drivers/solidfire.py

@@ -288,7 +288,7 @@ def _get_model_info(self, sfaccount, sf_volume_id):
 
         found_volume = False
         iteration_count = 0
-        while not found_volume and iteration_count < 10:
+        while not found_volume and iteration_count < 600:
             volume_list = self._get_volumes_by_sfaccount(
                 sfaccount['accountID'])
             iqn = None