btrfs: remove the second argument of k[un]map_atomic()

Signed-off-by: Cong Wang <amwang@redhat.com>
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index a55fbe6..2862454 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2546,10 +2546,10 @@
 
 		if (zero_offset) {
 			iosize = PAGE_CACHE_SIZE - zero_offset;
-			userpage = kmap_atomic(page, KM_USER0);
+			userpage = kmap_atomic(page);
 			memset(userpage + zero_offset, 0, iosize);
 			flush_dcache_page(page);
-			kunmap_atomic(userpage, KM_USER0);
+			kunmap_atomic(userpage);
 		}
 	}
 	while (cur <= end) {
@@ -2558,10 +2558,10 @@
 			struct extent_state *cached = NULL;
 
 			iosize = PAGE_CACHE_SIZE - pg_offset;
-			userpage = kmap_atomic(page, KM_USER0);
+			userpage = kmap_atomic(page);
 			memset(userpage + pg_offset, 0, iosize);
 			flush_dcache_page(page);
-			kunmap_atomic(userpage, KM_USER0);
+			kunmap_atomic(userpage);
 			set_extent_uptodate(tree, cur, cur + iosize - 1,
 					    &cached, GFP_NOFS);
 			unlock_extent_cached(tree, cur, cur + iosize - 1,
@@ -2607,10 +2607,10 @@
 			char *userpage;
 			struct extent_state *cached = NULL;
 
-			userpage = kmap_atomic(page, KM_USER0);
+			userpage = kmap_atomic(page);
 			memset(userpage + pg_offset, 0, iosize);
 			flush_dcache_page(page);
-			kunmap_atomic(userpage, KM_USER0);
+			kunmap_atomic(userpage);
 
 			set_extent_uptodate(tree, cur, cur + iosize - 1,
 					    &cached, GFP_NOFS);
@@ -2756,10 +2756,10 @@
 	if (page->index == end_index) {
 		char *userpage;
 
-		userpage = kmap_atomic(page, KM_USER0);
+		userpage = kmap_atomic(page);
 		memset(userpage + pg_offset, 0,
 		       PAGE_CACHE_SIZE - pg_offset);
-		kunmap_atomic(userpage, KM_USER0);
+		kunmap_atomic(userpage);
 		flush_dcache_page(page);
 	}
 	pg_offset = 0;