Blackfin: do not trace the exception handler

Since the exception handler cannot cause exceptions, we cannot trace it
without easily causing double faults and crashing the system.
Signed-off-by: NYi Li <yi.li@analog.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>

arch/blackfin/kernel/traps.c

@@ -257,7 +257,7 @@ static int kernel_mode_regs(struct pt_regs *regs)
 	return regs->ipend & 0xffc0;
 }
 
-asmlinkage void trap_c(struct pt_regs *fp)
+asmlinkage notrace void trap_c(struct pt_regs *fp)
 {
 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
 	int j;