mm/dmapool: use might_alloc()

Now that my little helper has landed, use it more.  On top of the existing
check this also uses lockdep through the fs_reclaim annotations.

Link: https://lkml.kernel.org/r/20210113135009.3606813-1-daniel.vetter@ffwll.chSigned-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/dmapool.c

@@ -28,6 +28,7 @@
 #include <linux/mutex.h>
 #include <linux/poison.h>
 #include <linux/sched.h>
+#include <linux/sched/mm.h>
 #include <linux/slab.h>
 #include <linux/stat.h>
 #include <linux/spinlock.h>
@@ -319,7 +320,7 @@ void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
 	size_t offset;
 	void *retval;
 
-	might_sleep_if(gfpflags_allow_blocking(mem_flags));
+	might_alloc(mem_flags);
 
 	spin_lock_irqsave(&pool->lock, flags);
 	list_for_each_entry(page, &pool->page_list, page_list) {