Bug 1192786 - add forgotten ifdeffery on CLOSED TREE. r=me

js/src/jit/arm/Assembler-arm.h

@@ -1383,7 +1383,9 @@ class Assembler : public AssemblerShared
     bool oom() const;
 
     void setPrinter(Sprinter* sp) {
+#ifdef JS_DISASM_ARM
         printer_ = sp;
+#endif
     }
 
     static const Register getStackPointer() {