tests: fix compilation warning

Signed-off-by: Loic Dachary <ldachary@redhat.com>

diff --git a/src/test/librbd/test_librbd.cc b/src/test/librbd/test_librbd.cc
index e4e3a1c69cdbefbf09ee04f8703608a4cc3b1f7e..dfb1fd4c41e14c1c45c7a8d721fa5305f3b8dd62 100644 (file)
--- a/src/test/librbd/test_librbd.cc
+++ b/src/test/librbd/test_librbd.cc
@@ -508,7 +508,7 @@ int test_ls_snaps(rbd_image_t image, int num_expected, ...)
   va_end(ap);
 
   for (i = 0; i < num_snaps; i++) {
-    EXPECT_EQ(NULL, snaps[i].name);
+    EXPECT_EQ((const char *)0, snaps[i].name);
   }
 
   return num_snaps;