[PATCH] tools/perf: Fix return code for lock_contention_prepare

[Athira Rajeev <atrajeev@linux.vnet.ibm.com>]

perf lock contention returns zero exit value even if the lock contention
BPF setup failed.

   # ./perf lock con -b true
   libbpf: kernel BTF is missing at '/sys/kernel/btf/vmlinux', was CONFIG_DEBUG_INFO_BTF enabled?
   libbpf: failed to find '.BTF' ELF section in /lib/modules/6.13.0-rc3+/build/vmlinux
   libbpf: failed to find valid kernel BTF
   libbpf: kernel BTF is missing at '/sys/kernel/btf/vmlinux', was CONFIG_DEBUG_INFO_BTF enabled?
   libbpf: failed to find '.BTF' ELF section in /lib/modules/6.13.0-rc3+/build/vmlinux
   libbpf: failed to find valid kernel BTF
   libbpf: Error loading vmlinux BTF: -ESRCH
   libbpf: failed to load object 'lock_contention_bpf'
   libbpf: failed to load BPF skeleton 'lock_contention_bpf': -ESRCH
   Failed to load lock-contention BPF skeleton
   lock contention BPF setup failed
   # echo $?
    0

Fix this by saving the return code for lock_contention_prepare
so that command exits with proper return code

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
---
 tools/perf/builtin-lock.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
index 208c482daa56..2226c7dd4ae6 100644
--- a/tools/perf/builtin-lock.c
+++ b/tools/perf/builtin-lock.c
@@ -2049,7 +2049,8 @@ static int __cmd_contention(int argc, const char **argv)
 				goto out_delete;
 		}
 
-		if (lock_contention_prepare(&con) < 0) {
+		err = lock_contention_prepare(&con);
+		if (err < 0) {
 			pr_err("lock contention BPF setup failed\n");
 			goto out_delete;
 		}
-- 
2.43.5