bpf, tests: Fix typos in comments

Currently, there are two comments with same name "64-bit ATOMIC magnitudes",
the second one should be "32-bit ATOMIC magnitudes" based on the context.
Signed-off-by: Chen Pei <cp0613@linux.alibaba.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20240415081928.17440-1-cp0613@linux.alibaba.com

lib/test_bpf.c

@@ -13431,7 +13431,7 @@ static struct bpf_test tests[] = {
 		.stack_depth = 8,
 		.nr_testruns = NR_PATTERN_RUNS,
 	},
-	/* 64-bit atomic magnitudes */
+	/* 32-bit atomic magnitudes */
 	{
 		"ATOMIC_W_ADD: all operand magnitudes",
 		{ },