selftests/bpf: by default use arch mask allowing all archs

If test case does not specify architecture via __arch_* macro consider
that it should be run for all architectures.

Fixes: 7d743e4c ("selftests/bpf: __jited test tag to check disassembly after jit")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240822084112.3257995-6-eddyz87@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/test_loader.c

@@ -543,7 +543,7 @@ static int parse_test_spec(struct test_loader *tester,
 		}
 	}
 
-	spec->arch_mask = arch_mask;
+	spec->arch_mask = arch_mask ?: -1;
 
 	if (spec->mode_mask == 0)
 		spec->mode_mask = PRIV;