Fix cpplint's whitespace warnings.

Change-Id: I16b69d773e59b49e8e30227b5aa5cb1959a8930f
diff --git a/src/runtime_linux.cc b/src/runtime_linux.cc
index 1461528..89fb627 100644
--- a/src/runtime_linux.cc
+++ b/src/runtime_linux.cc
@@ -47,7 +47,7 @@
   // "[0xf7b62057]"
 
   // We extract the pieces and demangle, so we can produce output like this:
-  // libartd.so:-1] 	#00 art::Runtime::PlatformAbort(char const*, int) +0x15b [0xf770dd51]
+  // libartd.so:-1]    #00 art::Runtime::PlatformAbort(char const*, int) +0x15b [0xf770dd51]
 
   for (size_t i = 0; i < frame_count; ++i) {
     std::string text(symbols[i]);