TEST: change target that runs filesystem example

Author: Qinghao Shi

tools/test/examples/examples.json

@@ -276,7 +276,7 @@
         "sub-repo-example": false,
         "subs": [],
         "features" : [],
-        "targets" : ["K64F","K82F"],
+        "targets" : ["DISCO_L475VG_IOT01A"],
         "toolchains" : [],
         "exporters": [],
         "compile" : true,