ia64/traps: Silence GCC warning about uninitialised variable

  arch/ia64/kernel/traps.c: In function 'ia64_fault':
  arch/ia64/kernel/traps.c:433:17: warning: 'siginfo.si_code' may be used uninitialized in this function [-Wmaybe-uninitialized]
    struct siginfo siginfo;

Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Bjorn Helgaas <helgaas@kernel.org>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: NTony Luck <tony.luck@intel.com>

arch/ia64/kernel/traps.c

@@ -548,6 +548,7 @@ ia64_fault (unsigned long vector, unsigned long isr, unsigned long ifa,
 			return;
 		}
 		switch (vector) {
+		      default:
 		      case 29:
 			siginfo.si_code = TRAP_HWBKPT;
 #ifdef CONFIG_ITANIUM