Fix a couple of gcc 4.8 warnings in tcmalloc.

third_party/tcmalloc/chromium/src/deep-heap-profile.cc

Index: third_party/tcmalloc/chromium/src/deep-heap-profile.cc
diff --git a/third_party/tcmalloc/chromium/src/deep-heap-profile.cc b/third_party/tcmalloc/chromium/src/deep-heap-profile.cc
index b27f1aa68bee7cd795db7ea0f36aa4db3a5c1abc..5a1392acdc4eeae1fb509d7bcd82d397b32a1478 100644
--- a/third_party/tcmalloc/chromium/src/deep-heap-profile.cc
+++ b/third_party/tcmalloc/chromium/src/deep-heap-profile.cc
@@ -127,8 +127,7 @@ void DeepHeapProfile::MemoryInfoGetterLinux::Initialize() {
   RAW_CHECK(pagemap_fd_ != -1, "Failed to open /proc/self/pagemap");
 
   if (pageframe_type_ == DUMP_PAGECOUNT) {
-    snprintf(filename, sizeof(filename), "/proc/kpagecount",
-             static_cast<int>(getpid()));

[jar (doing other things), 2014/01/29 02:33:12]

This looks like a bug.  How about fixing it with a %d to print the pid?

[Dai Mikurube (NOT FULLTIME), 2014/01/29 03:24:13]

Ah, yes. It's my bug. Thanks for working on it, Sam.

It doesn't need pid since /proc/kpagecount is kernel-level memory info., not
process memory info.

sbc@'s fix is correct, but just using "/proc/kpagecount" directly in open()
might be better.

+    snprintf(filename, sizeof(filename), "/proc/kpagecount");
     kpagecount_fd_ = open(filename, O_RDONLY);
     if (kpagecount_fd_ == -1)
       RAW_LOG(0, "Failed to open /proc/kpagecount");