Update slave scripts to set skia_arch_type but not skia_arch_width

scripts/slave/recipes/skia/skia.expected/failed_dm.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[DEPOT_TOOLS]/gclient.py",
       "config",
       "--spec",
       "cache_dir = None\nsolutions = [{'deps_file': 'DEPS', 'managed': True, 'name': 'skia', 'url': 'https://skia.googlesource.com/skia.git'}]"
     ],
@@ skipping 47 matching lines @@
   },
   {
     "cmd": [
       "make",
       "dm",
       "BUILDTYPE=Debug"
     ],
     "cwd": "[SLAVE_BUILD]/skia",
     "env": {
       "CHROME_PATH": "/home/chrome-bot/src",
-      "GYP_DEFINES": "skia_arch_type=x86_64 skia_arch_width=64 skia_gpu=0 skia_warnings_as_errors=0",
+      "GYP_DEFINES": "skia_arch_type=x86_64 skia_gpu=0 skia_warnings_as_errors=0",
       "SKIA_OUT": "[SLAVE_BUILD]/skia/out/Test-Ubuntu-GCC-ShuttleA-CPU-AVX-x86_64-Debug-Recipes"
     },
     "name": "build dm"
   },
   {
     "cmd": [
       "make",
       "nanobench",
       "BUILDTYPE=Debug"
     ],
     "cwd": "[SLAVE_BUILD]/skia",
     "env": {
       "CHROME_PATH": "/home/chrome-bot/src",
-      "GYP_DEFINES": "skia_arch_type=x86_64 skia_arch_width=64 skia_gpu=0 skia_warnings_as_errors=0",
+      "GYP_DEFINES": "skia_arch_type=x86_64 skia_gpu=0 skia_warnings_as_errors=0",
       "SKIA_OUT": "[SLAVE_BUILD]/skia/out/Test-Ubuntu-GCC-ShuttleA-CPU-AVX-x86_64-Debug-Recipes"
     },
     "name": "build nanobench"
   },
   {
     "cmd": [
       "python",
       "-u",
       "\nimport sys, os\npath = sys.argv[1]\nmode = int(sys.argv[2])\nif not os.path.isdir(path):\n  if os.path.exists(path):\n    print \"%s exists but is not a dir\" % path\n    sys.exit(1)\n  os.makedirs(path, mode)\n",
       "[SLAVE_BUILD]/tmp",
@@ skipping 266 matching lines @@
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "nanobench"
   },
   {
     "name": "$final_result",
     "reason": "Failed build steps: dm",
     "status_code": 1
   }
 ]