trace: fix multiple use of __print_flags and __print_symbolic

[Steven Whitehouse <swhiteho@redhat.com>]

When using multiple calls to __print_symbolic and __print_flags in
the same tracer, I noticed that the output was incorrect. I think
the following patch is the correct fix (it works for me) but please
check it carefully since I'm not that familiar with this code,
and I may well have made a mistake somewhere.

The patch is vs. the latest -tip tree which doesn't yet seem to
contain the EXPORT_SYMBOL() fix that I sent earlier.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>


diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index c12d95d..ac6ced1 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -222,10 +222,9 @@ ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
 {
 	unsigned long mask;
 	const char *str;
+	const char *ret = p->buffer + p->len;
 	int i;
 
-	trace_seq_init(p);
-
 	for (i = 0;  flag_array[i].name && flags; i++) {
 
 		mask = flag_array[i].mask;
@@ -248,7 +247,7 @@ ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
 
 	trace_seq_putc(p, 0);
 
-	return p->buffer;
+	return ret;
 }
 
 const char *
@@ -256,8 +255,7 @@ ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 			 const struct trace_print_flags *symbol_array)
 {
 	int i;
-
-	trace_seq_init(p);
+	const char *ret = p->buffer + p->len;
 
 	for (i = 0;  symbol_array[i].name; i++) {
 
@@ -273,7 +271,7 @@ ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 		
 	trace_seq_putc(p, 0);
 
-	return p->buffer;
+	return ret;
 }
 
 #ifdef CONFIG_KRETPROBES