[utils/FuzzTest] For --filelist the option type is string, not integer.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@152324 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/FuzzTest b/utils/FuzzTest
index 959182f..2b02bc1 100755
--- a/utils/FuzzTest
+++ b/utils/FuzzTest
@@ -223,7 +223,7 @@
                      type=str, action="append", dest="input_files", default=[])
     group.add_option("", "--filelist", metavar="LIST",
                      help="Add a list of inputs files to fuzz (one per line)",
-                     type=int, action="append", dest="filelists", default=[])
+                     type=str, action="append", dest="filelists", default=[])
     parser.add_option_group(group)
 
     group = OptionGroup(parser, "Fuzz Options")