Fix perfjit printf format for filename

TBR=jarin@chromium.org
LOG=n
BUG=none

Review URL: https://codereview.chromium.org/357333002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22102 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/perf-jit.cc

@@ -38,7 +38,7 @@ namespace internal {
 
 #ifdef __linux__
 
-const char PerfJitLogger::kFilenameFormatString[] = "perfjit.dump";
+const char PerfJitLogger::kFilenameFormatString[] = "perfjit-%d.dump";
 
 // Timestamp module name
 const char PerfJitLogger::kTraceClockDevice[] = "/dev/trace_clock";