Cleanup: Refactor the test of TEST_TMPDIR env variable.

No need to keep a separate variable at the top of the file, it is
simpler to just check the return value of getenv() directly in the call
site.

--
Change-Id: I896836206ccbf20743ef9679b10cec0cb7406122
MOS_MIGRATED_REVID=90505777

src/main/cpp/blaze.cc

diff --git a/src/main/cpp/blaze.cc b/src/main/cpp/blaze.cc
index 9e9e506..39dff42 100644
--- a/src/main/cpp/blaze.cc
+++ b/src/main/cpp/blaze.cc
@@ -76,9 +76,6 @@
 
 namespace blaze {
 
-// Blaze is being run by a test.
-static const bool TESTING = getenv("TEST_TMPDIR") != NULL;
-
 extern char **environ;
 
 ////////////////////////////////////////////////////////////////////////
@@ -1403,7 +1400,7 @@
     unsetenv("_JAVA_OPTIONS");
   }
 
-  if (TESTING) {
+  if (getenv("TEST_TMPDIR") != NULL) {
     fprintf(stderr, "INFO: $TEST_TMPDIR defined: output root default is "
                     "'%s'.\n", globals->options.output_root.c_str());
   }