configs: fix se.py error when using "--redirects"

Currently, the workload is initialized before host filesystem
redirections take place (i.e. before --redirects is taken into
account).

This change moves the initialization of the workload to the place
where the redirections have taken place.

JIRA: https://gem5.atlassian.net/browse/GEM5-1001

Change-Id: Id8f4c8486b4e0adb19ccc25d02d0c28cbf671063
Signed-off-by: Hoa Nguyen <hoanguyen@ucdavis.edu>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/46099
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

configs/example/se.py

@@ -166,8 +166,7 @@ mp0_path = multiprocesses[0].executable
 system = System(cpu = [CPUClass(cpu_id=i) for i in range(np)],
                 mem_mode = test_mem_mode,
                 mem_ranges = [AddrRange(args.mem_size)],
-                cache_line_size = args.cacheline_size,
-                workload = SEWorkload.init_compatible(mp0_path))
+                cache_line_size = args.cacheline_size)
 
 if numThreads > 1:
     system.multi_thread = True
@@ -262,6 +261,8 @@ else:
     MemConfig.config_mem(args, system)
     config_filesystem(system, args)
 
+system.workload = SEWorkload.init_compatible(mp0_path)
+
 if args.wait_gdb:
     for cpu in system.cpu:
         cpu.wait_for_remote_gdb = True