[sanitizer] Replace more platform checks with SANITIZER_ constants.

llvm-svn: 177400
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_procmaps.h b/compiler-rt/lib/sanitizer_common/sanitizer_procmaps.h
index 8df215d..fad254d 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_procmaps.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_procmaps.h
@@ -31,13 +31,13 @@
 };
 
 #else  // _WIN32
-#if defined(__linux__)
+#if SANITIZER_LINUX
 struct ProcSelfMapsBuff {
   char *data;
   uptr mmaped_size;
   uptr len;
 };
-#endif  // defined(__linux__)
+#endif  // SANITIZER_LINUX
 
 class MemoryMappingLayout {
  public: