MIPS: Remove unused task_struct.trap_no field.

It is initialized to zero and only ever read.  Remove it, and pass zero in
its place.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1531/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/processor.h

@@ -229,7 +229,6 @@ struct thread_struct {
 	unsigned long cp0_badvaddr;	/* Last user fault */
 	unsigned long cp0_baduaddr;	/* Last kernel fault accessing USEG */
 	unsigned long error_code;
-	unsigned long trap_no;
 	unsigned long irix_trampoline;  /* Wheee... */
 	unsigned long irix_oldctx;
 #ifdef CONFIG_CPU_CAVIUM_OCTEON
@@ -301,7 +300,6 @@ struct thread_struct {
 	.cp0_badvaddr		= 0,				\
 	.cp0_baduaddr		= 0,				\
 	.error_code		= 0,				\
-	.trap_no		= 0,				\
 	.irix_trampoline	= 0,				\
 	.irix_oldctx		= 0,				\
 	/*							\

arch/mips/kernel/asm-offsets.c

@@ -126,7 +126,6 @@ void output_thread_defines(void)
 	       thread.cp0_baduaddr);
 	OFFSET(THREAD_ECODE, task_struct, \
 	       thread.error_code);
-	OFFSET(THREAD_TRAPNO, task_struct, thread.trap_no);
 	OFFSET(THREAD_TRAMP, task_struct, \
 	       thread.irix_trampoline);
 	OFFSET(THREAD_OLDCTX, task_struct, \

arch/mips/kernel/traps.c

@@ -376,7 +376,7 @@ void __noreturn die(const char * str, struct pt_regs * regs)
 	mips_mt_regdump(dvpret);
 #endif /* CONFIG_MIPS_MT_SMTC */
 
-	if (notify_die(DIE_OOPS, str, regs, 0, current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
+	if (notify_die(DIE_OOPS, str, regs, 0, 0, SIGSEGV) == NOTIFY_STOP)
 		sig = 0;
 
 	printk("%s[#%d]:\n", str, ++die_counter);