dmaengine: Fix array index out of bounds warning in __get_unmap_pool()

BugLink: http://bugs.launchpad.net/bugs/1745052

[ Upstream commit 23f963e9 ]

This fixes the following warning when building with clang and
CONFIG_DMA_ENGINE_RAID=n :

drivers/dma/dmaengine.c:1102:11: error: array index 2 is past the end of the array (which contains 1 element) [-Werror,-Warray-bounds]
                return &unmap_pool[2];
                        ^          ~
drivers/dma/dmaengine.c:1083:1: note: array 'unmap_pool' declared here
static struct dmaengine_unmap_pool unmap_pool[] = {
^
drivers/dma/dmaengine.c:1104:11: error: array index 3 is past the end of the array (which contains 1 element) [-Werror,-Warray-bounds]
                return &unmap_pool[3];
                        ^          ~
drivers/dma/dmaengine.c:1083:1: note: array 'unmap_pool' declared here
static struct dmaengine_unmap_pool unmap_pool[] = {
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

drivers/dma/dmaengine.c

@@ -1023,12 +1023,14 @@ static struct dmaengine_unmap_pool *__get_unmap_pool(int nr)
 	switch (order) {
 	case 0 ... 1:
 		return &unmap_pool[0];
+#if IS_ENABLED(CONFIG_DMA_ENGINE_RAID)
 	case 2 ... 4:
 		return &unmap_pool[1];
 	case 5 ... 7:
 		return &unmap_pool[2];
 	case 8:
 		return &unmap_pool[3];
+#endif
 	default:
 		BUG();
 		return NULL;