Small bugfix to logging.h from Scott Ettinger.

Change-Id: Ie6d51e7883adf36c6fc7a78ff95afab6a78e488b

internal/ceres/miniglog/glog/logging.h

diff --git a/internal/ceres/miniglog/glog/logging.h b/internal/ceres/miniglog/glog/logging.h
index 9156d77..e43d05e 100644
--- a/internal/ceres/miniglog/glog/logging.h
+++ b/internal/ceres/miniglog/glog/logging.h
@@ -344,7 +344,7 @@
 
 // Generic binary operator check macro. This should not be directly invoked,
 // instead use the binary comparison macros defined below.
-#define CHECK_OP(val1, val2, op) LOG_IF_FALSE(FATAL, (val1 op val2)) \
+#define CHECK_OP(val1, val2, op) LOG_IF_FALSE(FATAL, ((val1) op (val2))) \
   << "Check failed: " #val1 " " #op " " #val2 " "
 
 // Check_op macro definitions