hw-breakpoints: fix undeclared ksym_tracer_mutex

ksym_tracer_mutex is declared inside an #ifdef CONFIG_PROFILE_KSYM_TRACER
section. This makes it unavailable for the hardware breakpoint tracer if it is
configured without the breakpoint profiler.

This patch fixes the following build error:

kernel/trace/trace_ksym.c: In function ‘ksym_trace_filter_read’:
kernel/trace/trace_ksym.c:226: erreur: ‘ksym_tracer_mutex’ undeclared (first use in this function)
kernel/trace/trace_ksym.c:226: erreur: (Each undeclared identifier is reported only once
kernel/trace/trace_ksym.c:226: erreur: for each function it appears in.)
kernel/trace/trace_ksym.c: In function ‘ksym_trace_filter_write’:
kernel/trace/trace_ksym.c:273: erreur: ‘ksym_tracer_mutex’ undeclared (first use in this function)
kernel/trace/trace_ksym.c: In function ‘ksym_trace_reset’:
kernel/trace/trace_ksym.c:335: erreur: ‘ksym_tracer_mutex’ undeclared (first use in this function)
make[1]: *** [kernel/trace/trace_ksym.o] Erreur 1

[ Impact: fix a build error ]
Reported-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>

kernel/trace/trace_ksym.c

@@ -44,12 +44,12 @@ static unsigned int ksym_tracing_enabled;
 
 static HLIST_HEAD(ksym_filter_head);
 
+static DEFINE_MUTEX(ksym_tracer_mutex);
+
 #ifdef CONFIG_PROFILE_KSYM_TRACER
 
 #define MAX_UL_INT 0xffffffff
 
-static DEFINE_MUTEX(ksym_tracer_mutex);
-
 void ksym_collect_stats(unsigned long hbp_hit_addr)
 {
 	struct hlist_node *node;