Make const ptr assign as function call in clang

- This can act as memory barrier in clang to avoid
  read before assign of a const ptr

Signed-off-by: LoveSy <shana@zju.edu.cn>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index 3c87abc..9960448 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -214,7 +214,7 @@
 #define delbuf           (S.delbuf          )
 
 #define INIT_S() do { \
-	ASSIGN_CONST_PTR(lineedit_ptr_to_statics, xzalloc(sizeof(S))); \
+	XZALLOC_CONST_PTR(&lineedit_ptr_to_statics, sizeof(S)); \
 } while (0)
 
 static void deinit_S(void)