Old kernel symbols dependency semantics broken

[NDStrahilevitz]

Previously, kernel symbols dependency semantics differentiated between three cases:

1. nil dependency - ksymbols irrelevant for the event.
2. empty array event - ksymbols required but none need to be preloaded specifically.
3. non-empty array - ksymbols required and specific symbols need to be preloaded.

Due to breaking this semantic, events such as print_mem_dump now fail when loading on their own:

tracee -e print_mem_dump.args.symbol_name=compat_filldir64
TIME             UID    COMM             PID     TID     RET              EVENT                     ARGS
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x20 pc=0x1ae51d1]

goroutine 1 [running]:
github.com/aquasecurity/tracee/pkg/ebpf.(*Tracee).triggerMemDump(_, {0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, ...})
        /home/ubuntu/tracee/pkg/ebpf/tracee.go:1691 +0xd91
github.com/aquasecurity/tracee/pkg/ebpf.(*Tracee).Run(0xc001952000, {0x315d968, 0xc000716140})
        /home/ubuntu/tracee/pkg/ebpf/tracee.go:1323 +0x165
github.com/aquasecurity/tracee/pkg/cmd.Runner.Run({{0xc000330000, 0xc000338070, 0xc00033b400, 0xc001d053d0, {0x0, 0x0}, 0x400, 0x400, 0x0, {0x0, ...}, ...}, ...}, ...)
        /home/ubuntu/tracee/pkg/cmd/tracee.go:87 +0x385
github.com/aquasecurity/tracee/cmd/tracee/cmd.glob..func4(0xc0007bfde0?, {0xc000040190?, 0x2?, 0x2?})
        /home/ubuntu/tracee/cmd/tracee/cmd/root.go:61 +0x258
github.com/spf13/cobra.(*Command).execute(0x3d39ac0, {0xc000040190, 0x2, 0x2})
        /home/ubuntu/go/pkg/mod/github.com/spf13/cobra@v1.7.0/command.go:944 +0x847
github.com/spf13/cobra.(*Command).ExecuteC(0x3d39ac0)
        /home/ubuntu/go/pkg/mod/github.com/spf13/cobra@v1.7.0/command.go:1068 +0x3bd
github.com/spf13/cobra.(*Command).Execute(...)
        /home/ubuntu/go/pkg/mod/github.com/spf13/cobra@v1.7.0/command.go:992
github.com/aquasecurity/tracee/cmd/tracee/cmd.Execute()
        /home/ubuntu/tracee/cmd/tracee/cmd/root.go:336 +0x34
main.main()
        /home/ubuntu/tracee/cmd/tracee/main.go:11 +0x19

[rafaeldtinoco]

Fix for this was reverted by #3436. I'm proposing a minor change that fixes this issue.