parisc: drop unnecessary cast in __ldcw_align() macro

__ldcw_align() can directly access the slock member of struct arch_spinlock_t
instead of using an ugly cast.
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

arch/parisc/include/asm/system.h

@@ -160,7 +160,7 @@ static inline void set_eiem(unsigned long val)
    ldcd). */
 
 #define __PA_LDCW_ALIGNMENT	4
-#define __ldcw_align(a) ((volatile unsigned int *)a)
+#define __ldcw_align(a) (&(a)->slock)
 #define __LDCW	"ldcw,co"
 
 #endif /*!CONFIG_PA20*/