[PATCH v2 bpf-next] selftests/bpf: Fix the invalid operand for instruction issue

[Feng Yang <yangfeng59949@163.com>]

From: Feng Yang <yangfeng@kylinos.cn>

The following issue occurs when compiling with clang version 17.0.6:
progs/compute_live_registers.c:251:3: error: invalid operand for instruction
  251 |                 "r0 = 1;"
      |                 ^
<inline asm>:1:22: note: instantiated into assembly here
    1 |         r0 = 1;r2 = 2;if r1 & 0x7 goto +1;exit;r0 = r2;exit;
      |                             ^
1 error generated.

Use __imm_insn to fix this issue.

Fixes: 4a4b84ba9e453 ("selftests/bpf: verify jset handling in CFG computation")
Signed-off-by: Feng Yang <yangfeng@kylinos.cn>
---
Changes in v2:
- Use __imm_insn, thanks: Eduard Zingerman.
- Link to v1: https://lore.kernel.org/all/20250827031540.461017-1-yangfeng59949@163.com/
---
 tools/testing/selftests/bpf/progs/compute_live_registers.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/compute_live_registers.c b/tools/testing/selftests/bpf/progs/compute_live_registers.c
index 6884ab99a421..01d73ad76faf 100644
--- a/tools/testing/selftests/bpf/progs/compute_live_registers.c
+++ b/tools/testing/selftests/bpf/progs/compute_live_registers.c
@@ -249,11 +249,13 @@ __naked void if3_jset_bug(void)
 	asm volatile (
 		"r0 = 1;"
 		"r2 = 2;"
-		"if r1 & 0x7 goto +1;"
+		".8byte %[jset];" /* same as 'if r1 & 0x7 goto +1;' */
 		"exit;"
 		"r0 = r2;"
 		"exit;"
-		::: __clobber_all);
+		:
+		: __imm_insn(jset, BPF_JMP_IMM(BPF_JSET, BPF_REG_1, 0x7, 1))
+		: __clobber_all);
 }
 
 SEC("socket")
-- 
2.43.0