Switch to g_ for globals.

That's what the Google style guide recommends, and we're starting
to get a mix.

Change-Id: Ib0c53a890bb5deed5c679e887541a715faea91fc
diff --git a/tests/unistd_test.cpp b/tests/unistd_test.cpp
index ff05039..3f31861 100644
--- a/tests/unistd_test.cpp
+++ b/tests/unistd_test.cpp
@@ -114,18 +114,18 @@
   ASSERT_EQ(123, sb.st_size);
 }
 
-static bool gPauseTestFlag = false;
+static bool g_pause_test_flag = false;
 static void PauseTestSignalHandler(int) {
-  gPauseTestFlag = true;
+  g_pause_test_flag = true;
 }
 
 TEST(unistd, pause) {
   ScopedSignalHandler handler(SIGALRM, PauseTestSignalHandler);
 
   alarm(1);
-  ASSERT_FALSE(gPauseTestFlag);
+  ASSERT_FALSE(g_pause_test_flag);
   ASSERT_EQ(-1, pause());
-  ASSERT_TRUE(gPauseTestFlag);
+  ASSERT_TRUE(g_pause_test_flag);
 }
 
 TEST(unistd, read) {