Fixed hipDeviceGetAttribute

1. Added negative test for hipDeviceGetAttribute
2. Fixed hipDeviceGetAttribute if int ptr input is null

Change-Id: I0e31f50fa407701fddf96e4eb64a87a371ff5d95

src/hip_device.cpp

@@ -155,6 +155,8 @@ hipError_t hipDeviceGetAttribute(int* pi, hipDeviceAttribute_t attr, int device)
 
     hipError_t e = hipSuccess;
 
+    if(pi != nullptr) {
+
     auto * hipDevice = ihipGetDevice(device);
     hipDeviceProp_t *prop = &hipDevice->_props;
     if (hipDevice) {
@@ -215,6 +217,9 @@ hipError_t hipDeviceGetAttribute(int* pi, hipDeviceAttribute_t attr, int device)
     } else {
         e = hipErrorInvalidDevice;
     }
+    }else{
+        e = hipErrorInvalidDevice;
+    }
     return ihipLogStatus(e);
 }