selftests/bpf: Convert test trace_printk to lskel.

Convert test trace_printk to light skeleton to check
rodata support in lskel.
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210514003623.28033-22-alexei.starovoitov@gmail.com

tools/testing/selftests/bpf/Makefile

@@ -313,7 +313,7 @@ LINKED_SKELS := test_static_linked.skel.h linked_funcs.skel.h		\
 		linked_vars.skel.h linked_maps.skel.h
 
 LSKELS := kfunc_call_test.c fentry_test.c fexit_test.c fexit_sleep.c \
-	test_ksyms_module.c test_ringbuf.c atomics.c
+	test_ksyms_module.c test_ringbuf.c atomics.c trace_printk.c
 SKEL_BLACKLIST += $$(LSKELS)
 
 test_static_linked.skel.h-deps := test_static_linked1.o test_static_linked2.o

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

@@ -3,7 +3,7 @@
 
 #include <test_progs.h>
 
-#include "trace_printk.skel.h"
+#include "trace_printk.lskel.h"
 
 #define TRACEBUF	"/sys/kernel/debug/tracing/trace_pipe"
 #define SEARCHMSG	"testing,testing"