MLBEDSW-6245: Bug fix fast storage allocator

Fast storage allocator did not always return an optimal
allocation.

Signed-off-by: Louis Verhaard <louis.verhaard@arm.com>
Change-Id: Ic758b6c4a82dc2633c4752b0c204a27ed36f651b
diff --git a/ethosu/vela/scheduler.py b/ethosu/vela/scheduler.py
index 3ef0d7f..284848f 100644
--- a/ethosu/vela/scheduler.py
+++ b/ethosu/vela/scheduler.py
@@ -1152,7 +1152,7 @@
         if ix >= len(self.lrs):
             if alloc_size > self.best_allocated_size:
                 self.best_allocated_size = alloc_size
-                self.evicted = self.curr_evicted
+                self.evicted = self.curr_evicted.copy()
             return
 
         lr = self.lrs[ix]