testing/setup-googletest.h: Explicitly ignore the result of RUN_ALL_TESTS

To silence a warning, explicitly ignore the return value of `RUN_ALL_TESTS`: we
exit on failure anyway, the return value isn't useful for us in any way.

Signed-off-by: Gergely Nagy <algernon@keyboard.io>

testing/setup-googletest.h

@@ -36,5 +36,7 @@
     /* Turn off virtual_io's input. */ \
     Kaleidoscope.device().keyScanner().setEnableReadMatrix(false); \
     testing::InitGoogleTest(); \
-    RUN_ALL_TESTS(); \
+    /* We assign the return value of RUN_ALL_TESTS, to */ \
+    /* silence a compiler warning. */                     \
+    int __ignore__ = RUN_ALL_TESTS();           \
   }