gpu: ion: IOCTL return success when error occurs

ION_IOC_MAP, ION_IOC_SHARE, and ION_IOC_IMPORT may return
success when an error occurs.

Add correct error handling to ION_IOC_MAP, ION_IOC_SHARE, and
ION_IOC_IMPORT.
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
[jstultz: modified patch to apply to staging directory]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/ion/ion.c

@@ -1040,20 +1040,27 @@ static long ion_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		data.fd = ion_share_dma_buf(client, data.handle);
 		if (copy_to_user((void __user *)arg, &data, sizeof(data)))
 			return -EFAULT;
+		if (data.fd < 0)
+			return data.fd;
 		break;
 	}
 	case ION_IOC_IMPORT:
 	{
 		struct ion_fd_data data;
+		int ret = 0;
 		if (copy_from_user(&data, (void __user *)arg,
 				   sizeof(struct ion_fd_data)))
 			return -EFAULT;
 		data.handle = ion_import_dma_buf(client, data.fd);
-		if (IS_ERR(data.handle))
+		if (IS_ERR(data.handle)) {
+			ret = PTR_ERR(data.handle);
 			data.handle = NULL;
+		}
 		if (copy_to_user((void __user *)arg, &data,
 				 sizeof(struct ion_fd_data)))
 			return -EFAULT;
+		if (ret < 0)
+			return ret;
 		break;
 	}
 	case ION_IOC_SYNC: