Remove extra quoting from the Linux GN platform filter.

DEPS

 # This file is automatically processed to create .DEPS.git which is the file
 # that gclient uses under git.
 #
 # See http://code.google.com/p/chromium/wiki/UsingGit
 #
 # To test manually, run:
 #   python tools/deps2git/deps2git.py -o .DEPS.git
 #   gclient runhooks
 # DO NOT CHECK IN CHANGES TO .DEPS.git. It will be automatically updated by
 # a bot when you modify this one.
@@ skipping 615 matching lines @@
                 "--platform=win32",
                 "--directory",
                 "--bucket", "chromium-gn",
                 "src/tools/gn/bin/win",
     ],
   },
   {
     "name": "gn_linux",
     "pattern": "\\.sha1$",
     "action": [ "download_from_google_storage",
-                "--platform=\"linux*\"",
+                "--platform=linux*",
                 "--directory",
                 "--bucket", "chromium-gn",
                 "src/tools/gn/bin/linux",
     ],
   },
   {
     # A change to a .gyp, .gypi, or to GYP itself should run the generator.
     "name": "gyp",
     "pattern": ".",
     "action": ["python", "src/build/gyp_chromium"],
   },
   {
     # Check for landmines (reasons to clobber the build).
     "name": "landmines",
     "pattern": ".",
     "action": ["python", "src/build/landmines.py"],
   },
 ]