[ARM] Remove an extraneous load from atomic ops

atomic.h was generating some extra loads that aren't required.  In
addition, it was needlessly performing various tests inside the
atomic region.  This change fixes both these issues.

include/asm-arm/atomic.h

@@ -71,27 +71,27 @@ static __inline__ void atomic_dec(volatile atomic_t *v)
 static __inline__ int atomic_dec_and_test(volatile atomic_t *v)
 {
 	unsigned long flags;
-	int result;
+	int val;
 
 	__save_flags_cli(flags);
-	v->counter -= 1;
-	result = (v->counter == 0);
+	val = v->counter;
+	v->counter = val -= 1;
 	__restore_flags(flags);
 
-	return result;
+	return val == 0;
 }
 
 static inline int atomic_add_negative(int i, volatile atomic_t *v)
 {
 	unsigned long flags;
-	int result;
+	int val;
 
 	__save_flags_cli(flags);
-	v->counter += i;
-	result = (v->counter < 0);
+	val = v->counter;
+	v->counter = val += i;
 	__restore_flags(flags);
 
-	return result;
+	return val < 0;
 }
 
 static __inline__ void atomic_clear_mask(unsigned long mask, unsigned long *addr)