sh: Shut up SH2-DSP compile warnings.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/kernel/traps.c b/arch/sh/kernel/traps.c
index 299b8cf..9c7fb92 100644
--- a/arch/sh/kernel/traps.c
+++ b/arch/sh/kernel/traps.c
@@ -614,7 +614,7 @@
  */
 int is_dsp_inst(struct pt_regs *regs)
 {
-	unsigned short inst;
+	unsigned short inst = 0;
 
 	/*
 	 * Safe guard if DSP mode is already enabled or we're lacking