Fix readme --distributed -> --model (#1187)
Summary:
Accidentally had --distributed as argument instead of --model
Pull Request resolved: https://github.com/pytorch/benchmark/pull/1187
Reviewed By: xuzhao9
Differential Revision: D39593458
Pulled By: erichan1
fbshipit-source-id: fbf96b23f5a88aa0b0b56c767df249103d810990