selftests/bpf: Fix trivial typo

Fix trivial typo in comment from 'oveflow' to 'overflow'.

Reported-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Drew Fustini <dfustini@baylibre.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211122070528.837806-1-dfustini@baylibre.com

tools/testing/selftests/bpf/prog_tests/btf_dump.c

@@ -756,7 +756,7 @@ static void test_btf_dump_struct_data(struct btf *btf, struct btf_dump *d,
 	/* overflow bpf_sock_ops struct with final element nonzero/zero.
 	 * Regardless of the value of the final field, we don't have all the
 	 * data we need to display it, so we should trigger an overflow.
-	 * In other words oveflow checking should trump "is field zero?"
+	 * In other words overflow checking should trump "is field zero?"
 	 * checks because if we've overflowed, it shouldn't matter what the
 	 * field is - we can't trust its value so shouldn't display it.
 	 */