kernel/hw_breakpoint.c: Fix local/global shadowing

If the new percpu tree is combined with the perf events tree
the following new warning triggers:

 kernel/hw_breakpoint.c: In function 'toggle_bp_task_slot':
 kernel/hw_breakpoint.c:151: warning: 'task_bp_pinned' is used uninitialized in this function

Because it's not valid anymore to define a local variable
and a percpu variable (even if it's file scope local) with
the same name.

Rename the local variable to resolve this.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <200911260701.nAQ71owx016356@imap1.linux-foundation.org>
[ v2: added changelog ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/hw_breakpoint.c

@@ -121,7 +121,7 @@ static void toggle_bp_task_slot(struct task_struct *tsk, int cpu, bool enable)
 	int count = 0;
 	struct perf_event *bp;
 	struct perf_event_context *ctx = tsk->perf_event_ctxp;
-	unsigned int *task_bp_pinned;
+	unsigned int *tsk_pinned;
 	struct list_head *list;
 	unsigned long flags;
 
@@ -146,15 +146,15 @@ static void toggle_bp_task_slot(struct task_struct *tsk, int cpu, bool enable)
 	if (WARN_ONCE(count < 0, "No breakpoint counter found in the counter list"))
 		return;
 
-	task_bp_pinned = per_cpu(task_bp_pinned, cpu);
+	tsk_pinned = per_cpu(task_bp_pinned, cpu);
 	if (enable) {
-		task_bp_pinned[count]++;
+		tsk_pinned[count]++;
 		if (count > 0)
-			task_bp_pinned[count-1]--;
+			tsk_pinned[count-1]--;
 	} else {
-		task_bp_pinned[count]--;
+		tsk_pinned[count]--;
 		if (count > 0)
-			task_bp_pinned[count-1]++;
+			tsk_pinned[count-1]++;
 	}
 }