ll_prof: Do not use the deprecated tempfile.mktemp()

BUG=v8:1306
LOG=Y

Review URL: https://codereview.chromium.org/1411053002

Cr-Commit-Position: refs/heads/master@{#31382}

tools/disasm.py

@@ -60,7 +60,9 @@ def GetDisasmLines(filename, offset, size, arch, inplace, arch_flags=""):
     # Create a temporary file containing a copy of the code.
     assert arch in _ARCH_MAP, "Unsupported architecture '%s'" % arch
     arch_flags = arch_flags + " " +  _ARCH_MAP[arch]
-    tmp_name = tempfile.mktemp(".v8code")
+    tmp_file = tempfile.NamedTemporaryFile(prefix=".v8code", delete=False)
+    tmp_name = tmp_file.name
+    tmp_file.close()
     command = "dd if=%s of=%s bs=1 count=%d skip=%d && " \
               "%s %s -D -b binary %s %s" % (
       filename, tmp_name, size, offset,