[ Upstream commit95b079d821] Fix the type of index from unsigned int to int since find_slots() might return -1. Fixes:26a7e09478("swiotlb: refactor swiotlb_tbl_map_single") Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Claire Chang <tientzu@chromium.org> Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> (cherry picked from commita01572e21f) Signed-off-by: Greg Kroah-Hartman <gregkh@google.com> Change-Id: I352263b74ff89334c1e3fd6f1b70e1c08b7f2b47