ARM: get rid of horrible *(unsigned int *)(regs + 1)

Get rid of the horrible "*(unsigned int *)(regs + 1)" to get at the
parent context domain access register value, instead using the newly
introduced svc_pt_regs structure.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

arch/arm/include/asm/ptrace.h

@@ -25,6 +25,8 @@ struct svc_pt_regs {
 	u32 unused;
 };
 
+#define to_svc_pt_regs(r) container_of(r, struct svc_pt_regs, regs)
+
 #define user_mode(regs)	\
 	(((regs)->ARM_cpsr & 0xf) == 0)