sh: correct definitions to access stack pointers

A definition like:

#define regs_return_value(regs)	((regs)->regs[0])

called with regs_return_value(foo) will be preprocessed to:

((foo)->foo[0])
        ^^^
So to fix this to ensure the preprocessor compiles such calls correctly.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/include/asm/ptrace_64.h

@@ -13,7 +13,7 @@ struct pt_regs {
 #ifdef __KERNEL__
 
 #define MAX_REG_OFFSET		offsetof(struct pt_regs, tregs[7])
-#define regs_return_value(regs)	((regs)->regs[3])
+#define regs_return_value(_regs)	((_regs)->regs[3])
 
 #endif /* __KERNEL__ */