btrfs: declare rsv_count as unsigned int instead of int

rsv_count ultimately gets passed to start_transaction() which
now takes an unsigned int as its num_items parameter.
The value of rsv_count should always be positive so declare it
as being unsigned.

Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index b6695c4..7031e96 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2263,7 +2263,7 @@
 	u64 drop_end;
 	int ret = 0;
 	int err = 0;
-	int rsv_count;
+	unsigned int rsv_count;
 	bool same_page;
 	bool no_holes = btrfs_fs_incompat(root->fs_info, NO_HOLES);
 	u64 ino_size;