Adds the proper MODULE_IMPORT_NS(DMA_BUF) line to the file to get it to
build properly.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Link: https://lore.kernel.org/r/20211027154843.622961fd@canb.auug.org.auSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>