drm/vmwgfx: Return the correct value in vmw_translate_ptr functions

In the Linux kernel, the following vulnerability has been resolved: drm/vmwgfx: Return the correct value in vmw_translate_ptr functions Before the referenced fixes these functions used a lookup function that returned a pointer. This was changed to another lookup function that returned an error code with the pointer becoming an out parameter. The error path when the lookup failed was not changed to reflect this change and the code continued to return the PTR_ERR of the now uninitialized pointer. This could cause the vmw_translate_ptr functions to return success when they actually failed causing further uninitialized and OOB accesses.