f2fs/crypto: drop crypto key at evict_inode only

This patch avoids dropping crypto key in f2fs_drop_inode, so we can guarantee
it happens only at evict_inode.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index b5143f7..82523f9 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -673,7 +673,6 @@
 
 			sb_end_intwrite(inode->i_sb);
 
-			fscrypt_put_encryption_info(inode, NULL);
 			spin_lock(&inode->i_lock);
 			atomic_dec(&inode->i_count);
 		}