trace: add variant without spacing in trace_print_hex_seq

For upcoming tracepoint support for BPF, we want to dump the program's
tag. Format should be similar to __print_hex(), but without spacing.
Add a __print_hex_str() variant for exactly that purpose that reuses
trace_print_hex_seq().

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 5d33a73..30a144b1 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -163,14 +163,15 @@ trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
 EXPORT_SYMBOL_GPL(trace_print_bitmask_seq);
 
 const char *
-trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
+trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len,
+		    bool spacing)
 {
 	int i;
 	const char *ret = trace_seq_buffer_ptr(p);
 
 	for (i = 0; i < buf_len; i++)
-		trace_seq_printf(p, "%s%2.2x", i == 0 ? "" : " ", buf[i]);
-
+		trace_seq_printf(p, "%s%2.2x", !spacing || i == 0 ? "" : " ",
+				 buf[i]);
 	trace_seq_putc(p, 0);
 
 	return ret;