samples/bpf: change _kern suffix to .bpf with BPF test programs

This commit changes the _kern suffix to .bpf with the BPF test programs.
With this modification, test programs will inherit the benefit of the
new CLANG-BPF compile target.

Signed-off-by: Daniel T. Lee <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Alexei Starovoitov <[e-mail]>

samples/bpf/Makefile

···
 always-y += tracex5_kern.o
 always-y += tracex6_kern.o
 always-y += tracex7_kern.o
-always-y += sock_flags_kern.o
+always-y += sock_flags.bpf.o
 always-y += test_probe_write_user.bpf.o
 always-y += trace_output.bpf.o
 always-y += tcbpf1_kern.o
···
 always-y += offwaketime_kern.o
 always-y += spintest_kern.o
 always-y += map_perf_test.bpf.o
-always-y += test_overhead_tp_kern.o
-always-y += test_overhead_raw_tp_kern.o
-always-y += test_overhead_kprobe_kern.o
+always-y += test_overhead_tp.bpf.o
+always-y += test_overhead_raw_tp.bpf.o
+always-y += test_overhead_kprobe.bpf.o
 always-y += parse_varlen.o parse_simple.o parse_ldabs.o
-always-y += test_cgrp2_tc_kern.o
+always-y += test_cgrp2_tc.bpf.o
 always-y += xdp1_kern.o
 always-y += xdp2_kern.o
 always-y += test_current_task_under_cgroup.bpf.o
 always-y += trace_event_kern.o
 always-y += sampleip_kern.o
-always-y += lwt_len_hist_kern.o
+always-y += lwt_len_hist.bpf.o
 always-y += xdp_tx_iptunnel_kern.o
-always-y += test_map_in_map_kern.o
+always-y += test_map_in_map.bpf.o
 always-y += tcp_synrto_kern.o
 always-y += tcp_rwnd_kern.o
 always-y += tcp_bufs_kern.o

samples/bpf/lwt_len_hist.sh

···
 NS1=lwt_ns1
 VETH0=tst_lwt1a
 VETH1=tst_lwt1b
-BPF_PROG=lwt_len_hist_kern.o
+BPF_PROG=lwt_len_hist.bpf.o
 TRACE_ROOT=/sys/kernel/debug/tracing
 
 function cleanup {

samples/bpf/test_cgrp2_sock2.sh

···
 MY_DIR=$(dirname $0)
 TEST=$MY_DIR/test_cgrp2_sock2
 LINK_PIN=$BPFFS/test_cgrp2_sock2
-BPF_PROG=$MY_DIR/sock_flags_kern.o
+BPF_PROG=$MY_DIR/sock_flags.bpf.o
 
 function config_device {
 	ip netns add at_ns0

samples/bpf/test_cgrp2_tc.sh

···
 MY_DIR=$(dirname $0)
 # Details on the bpf prog
 BPF_CGRP2_ARRAY_NAME='test_cgrp2_array_pin'
-BPF_PROG="$MY_DIR/test_cgrp2_tc_kern.o"
+BPF_PROG="$MY_DIR/test_cgrp2_tc.bpf.o"
 BPF_SECTION='filter'
 
 [ -z "$TC" ] && TC='tc'

samples/bpf/test_map_in_map_user.c

···
 	struct bpf_object *obj;
 	char filename[256];
 
-	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
 	obj = bpf_object__open_file(filename, NULL);
 	if (libbpf_get_error(obj)) {
 		fprintf(stderr, "ERROR: opening BPF object file failed\n");

samples/bpf/test_overhead_user.c

···
 
 	if (test_flags & 0xC) {
 		snprintf(filename, sizeof(filename),
-			 "%s_kprobe_kern.o", argv[0]);
+			 "%s_kprobe.bpf.o", argv[0]);
 
 		printf("w/KPROBE\n");
 		err = load_progs(filename);
···
 
 	if (test_flags & 0x30) {
 		snprintf(filename, sizeof(filename),
-			 "%s_tp_kern.o", argv[0]);
+			 "%s_tp.bpf.o", argv[0]);
 		printf("w/TRACEPOINT\n");
 		err = load_progs(filename);
 		if (!err)
···
 
 	if (test_flags & 0xC0) {
 		snprintf(filename, sizeof(filename),
-			 "%s_raw_tp_kern.o", argv[0]);
+			 "%s_raw_tp.bpf.o", argv[0]);
 		printf("w/RAW_TRACEPOINT\n");
 		err = load_progs(filename);
 		if (!err)