fix to previous patch.  detect non-constant initializers even if constant
reduction is not done

Reference: /n/atom/patch/applied/dcl2
Date: Thu Apr 23 15:19:39 CES 2015
Signed-off-by: quanstro@quanstro.net

--- /sys/src/cmd/cc/dcl.c	Thu Apr 23 15:18:59 2015
+++ /sys/src/cmd/cc/dcl.c	Thu Apr 23 15:19:01 2015
@@ -381,11 +381,12 @@
 				diag(a, "initialization of incompatible pointers: %s\n%T and %T",
 					s->name, t, a->type);
 			}
-			if(a->op == OADDR) {
+			switch(a->op){
+			case OADDR:
 				a = a->left;
-				goto gext;
-			}
-			if(a->type->etype == TIND) {
+				break;
+			case ONAME:
+			case OIND:
 				diag(a, "initializer is not a constant: %s", s->name);
 				return Z;
 			}