bpflbr: Trim LBR entries when exit mode

When the trace target is bpf prog, trim LBR entries when `--mode` is
`exit`, as no bpf prog's entries when `--mode` is `entry`.

Signed-off-by: Leon Hwang <[email protected]>

internal/bpflbr/lbr.go

@@ -172,7 +172,7 @@ func getLbrStack(event *Event, progs *bpfProgs, addr2line *Addr2Line, ksyms *Kal
 
 		entries = entries[nrSkip:]
 
-		if isProg {
+		if isProg && mode == TracingModeExit {
 			for i := range entries {
 				if progInfo.contains(entries[i].From) || progInfo.contains(entries[i].To) {
 					entries = entries[i:]