x86: Mark ptrace_get_debugreg() as static

This sparse warning:

  arch/x86/kernel/ptrace.c:560:15: warning: symbol 'ptrace_get_debugreg' was not declared. Should it be static?

triggers because ptrace_get_debugreg() is global but is only
used in a single .c file. change ptrace_get_debugreg() to
static to fix that - this also addresses the sparse warning.
Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1246458150.6940.19.camel@hpdv5.satnam>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/ptrace.c

@@ -557,7 +557,7 @@ static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
 /*
  * Handle PTRACE_PEEKUSR calls for the debug register area.
  */
-unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
+static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
 {
 	struct thread_struct *thread = &(tsk->thread);
 	unsigned long val = 0;