Add conditional reschedules to env_sort

Sorting can take a long time with big cache sizes and a lot of dirty
data. Make sure we reschedule frome time to time to avoid lockups.

Signed-off-by: Jan Musial <jan.musial@intel.com>

modules/cas_cache/ocf_env.c

@@ -275,6 +275,7 @@ void env_sort(void *base, size_t num, size_t size,
 				break;
 			swap_fn(base + r, base + c, size);
 		}
+		env_cond_resched();
 	}
 
 	/* sort */
@@ -289,5 +290,6 @@ void env_sort(void *base, size_t num, size_t size,
 				break;
 			swap_fn(base + r, base + c, size);
 		}
+		env_cond_resched();
 	}
 }