gralloc: avoid Null pointer dereference.

- getMetaData checks for Null param and returns error. It may lead to
  Null pointer dereference in getMapSecureBufferFlag and getInterlacedFlag.

Change-Id: Ic6ae66198ba01c50b6f30086fcc35f2cf39cfb69
diff --git a/gralloc/QtiMapper.cpp b/gralloc/QtiMapper.cpp
index dc1b40c..dba446a 100644
--- a/gralloc/QtiMapper.cpp
+++ b/gralloc/QtiMapper.cpp
@@ -266,30 +266,30 @@
 Return<void> QtiMapper::getMapSecureBufferFlag(void *buffer, getMapSecureBufferFlag_cb hidl_cb) {
   auto err = Error::BAD_BUFFER;
   auto hnd = static_cast<private_handle_t *>(buffer);
-  int *map_secure_buffer = 0;
+  int map_secure_buffer = 0;
   if (buffer != nullptr && private_handle_t::validate(hnd) == 0) {
-    if (getMetaData(hnd, GET_MAP_SECURE_BUFFER, map_secure_buffer) != 0) {
-      *map_secure_buffer = 0;
+    if (getMetaData(hnd, GET_MAP_SECURE_BUFFER, &map_secure_buffer) != 0) {
+      map_secure_buffer = 0;
     } else {
       err = Error::NONE;
     }
   }
-  hidl_cb(err, *map_secure_buffer != 0);
+  hidl_cb(err, map_secure_buffer != 0);
   return Void();
 }
 
 Return<void> QtiMapper::getInterlacedFlag(void *buffer, getInterlacedFlag_cb hidl_cb) {
   auto err = Error::BAD_BUFFER;
   auto hnd = static_cast<private_handle_t *>(buffer);
-  int *interlaced_flag = nullptr;
+  int interlaced_flag = 0;
   if (buffer != nullptr && private_handle_t::validate(hnd) == 0) {
-    if (getMetaData(hnd, GET_PP_PARAM_INTERLACED, interlaced_flag) != 0) {
-      *interlaced_flag = 0;
+    if (getMetaData(hnd, GET_PP_PARAM_INTERLACED, &interlaced_flag) != 0) {
+      interlaced_flag = 0;
     } else {
       err = Error::NONE;
     }
   }
-  hidl_cb(err, *interlaced_flag != 0);
+  hidl_cb(err, interlaced_flag != 0);
   return Void();
 }