The bpf_csum_diff() helper has been fixed to return a 16-bit value for
all archs, so now we don't need to mask the result.
...
--- a/tools/testing/selftests/bpf/progs/verifier_array_access.c
+++ b/tools/testing/selftests/bpf/progs/verifier_array_access.c
@@ -368,8 +368,7 @@ __naked void a_read_only_array_2_1(void)
r4 = 0; \
r5 = 0; \
call %[bpf_csum_diff]; \
-l0_%=: r0 &= 0xffff; \
- exit; \
+l0_%=: exit; \