NFS: Fix memory leaks

In _nfs42_proc_copy(), 'res->commit_res.verf' is allocated through
kzalloc() if 'args->sync' is true. In the following code, if
'res->synchronous' is false, handle_async_copy() will be invoked. If an
error occurs during the invocation, the following code will not be executed
and the error will be returned . However, the allocated
'res->commit_res.verf' is not deallocated, leading to a memory leak. This
is also true if the invocation of process_copy_commit() returns an error.

To fix the above leaks, redirect the execution to the 'out' label if an
error is encountered.
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/nfs42proc.c

@@ -343,14 +343,14 @@ static ssize_t _nfs42_proc_copy(struct file *src,
 		status = handle_async_copy(res, dst_server, src_server, src,
 				dst, &args->src_stateid, restart);
 		if (status)
-			return status;
+			goto out;
 	}
 
 	if ((!res->synchronous || !args->sync) &&
 			res->write_res.verifier.committed != NFS_FILE_SYNC) {
 		status = process_copy_commit(dst, pos_dst, res);
 		if (status)
-			return status;
+			goto out;
 	}
 
 	truncate_pagecache_range(dst_inode, pos_dst,