Always output zero-terminator in slangdata.py.

Output one more byte '\0' can be useful when the input data file is
a bitcode file. With the existence of '\0', we can use

        llvm::MemoryBuffer::getMemBuffer()

                    instead of

        llvm::MemoryBuffer::getMemBufferCopy()

to prepare buffer for llvm::ParseBitcodeFile(llvm::MemoryBuffer, ...).
diff --git a/slangdata.py b/slangdata.py
index 2486ff4..a23b26c 100755
--- a/slangdata.py
+++ b/slangdata.py
@@ -61,9 +61,9 @@
         sys.stdout.write(", ")
       else:
         sys.stdout.write(",")
-  # always ends with 0x0 (can fix assembler warnings)
+  # always ends with 0x0
+  sys.stdout.write("0x00")
   if col != 0:
-    sys.stdout.write("0x00")
     sys.stdout.write("\n")
 
   # encode file size