drm/prime: fix comment on PRIME Helpers

s/Exporting/Importing

Fixes: 805dc614 ("drm/prime: Update docs")
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Jose Maria Casanova Crespo <jmcasanova@igalia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210723123307.31064-1-jmcasanova@igalia.com

drivers/gpu/drm/drm_prime.c

@@ -549,7 +549,7 @@ int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data,
  *
  * FIXME: The underlying helper functions are named rather inconsistently.
  *
- * Exporting buffers
+ * Importing buffers
  * ~~~~~~~~~~~~~~~~~
  *
  * Importing dma-bufs using drm_gem_prime_import() relies on