kernel/cgroup.c: kfree(NULL) is legal

Reduces object file size a bit:

Before:
$ size kernel/cgroup.o
   text    data     bss     dec     hex filename
  21593    7804    4924   34321    8611 kernel/cgroup.o
After:
$ size kernel/cgroup.o
   text    data     bss     dec     hex filename
  21537    7744    4924   34205    859d kernel/cgroup.o
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/cgroup.c

@@ -923,7 +923,6 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data)
 	if (opts.release_agent)
 		strcpy(root->release_agent_path, opts.release_agent);
  out_unlock:
-	if (opts.release_agent)
 	kfree(opts.release_agent);
 	mutex_unlock(&cgroup_mutex);
 	mutex_unlock(&cgrp->dentry->d_inode->i_mutex);
@@ -1027,14 +1026,12 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
 	/* First find the desired set of subsystems */
 	ret = parse_cgroupfs_options(data, &opts);
 	if (ret) {
-		if (opts.release_agent)
 		kfree(opts.release_agent);
 		return ret;
 	}
 
 	root = kzalloc(sizeof(*root), GFP_KERNEL);
 	if (!root) {
-		if (opts.release_agent)
 		kfree(opts.release_agent);
 		return -ENOMEM;
 	}