fix atomic operations on sparc64 built by SunPro C

src/os/unix/ngx_sunpro_atomic_sparc64.h

diff --git a/src/os/unix/ngx_sunpro_atomic_sparc64.h b/src/os/unix/ngx_sunpro_atomic_sparc64.h
index db85211..b126030 100644
--- a/src/os/unix/ngx_sunpro_atomic_sparc64.h
+++ b/src/os/unix/ngx_sunpro_atomic_sparc64.h
@@ -24,7 +24,7 @@
 ngx_atomic_cmp_set(ngx_atomic_t *lock, ngx_atomic_uint_t old,
     ngx_atomic_uint_t set)
 {
-    NGX_CASA(set, old, lock);
+    set = NGX_CASA(set, old, lock);
 
     return (set == old);
 }
@@ -41,7 +41,7 @@
 
         res = old + add;
 
-        NGX_CASA(res, old, value);
+        res = NGX_CASA(res, old, value);
 
         if (res == old) {
             return res;