kgdb/x86: Fix reporting of 'si' in kgdb on x86_64

This patch fixes an error in kgdb for x86_64 which would report
the value of dx when asked to give the value of si.

Signed-off-by: Steffen Liebergeld <steffen.liebergeld@kernkonzept.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/kgdb.c

@@ -72,7 +72,7 @@ struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
 	{ "bx", 8, offsetof(struct pt_regs, bx) },
 	{ "cx", 8, offsetof(struct pt_regs, cx) },
 	{ "dx", 8, offsetof(struct pt_regs, dx) },
-	{ "si", 8, offsetof(struct pt_regs, dx) },
+	{ "si", 8, offsetof(struct pt_regs, si) },
 	{ "di", 8, offsetof(struct pt_regs, di) },
 	{ "bp", 8, offsetof(struct pt_regs, bp) },
 	{ "sp", 8, offsetof(struct pt_regs, sp) },