Need to check the return value of proc_put_char(), as was done in
__do_proc_doulongvec_minmax().
Signed-off-by: NChen Gang <gang.chen@asianux.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>