[PATCH -next] mm/hmm: remove set but not used variable 'devmem'

[YueHaibing]

Fixes gcc '-Wunused-but-set-variable' warning:

mm/hmm.c: In function 'hmm_devmem_ref_kill':
mm/hmm.c:995:21: warning:
 variable 'devmem' set but not used [-Wunused-but-set-variable]

It not used any more since commit 35d39f953d4e ("mm, hmm: replace
hmm_devmem_pages_create() with devm_memremap_pages()")

Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx>
---
 mm/hmm.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/mm/hmm.c b/mm/hmm.c
index 50fbaf8..361f370 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -992,9 +992,6 @@ static void hmm_devmem_ref_exit(void *data)
 
 static void hmm_devmem_ref_kill(struct percpu_ref *ref)
 {
-	struct hmm_devmem *devmem;
-
-	devmem = container_of(ref, struct hmm_devmem, ref);
 	percpu_ref_kill(ref);
 }