drivers/message/i2o/i2o_proc.c: the pointer returned from chtostr() points to an array which is no longer valid

...  when being used in the calling function.  Although it may work, the
behavior is undefined.  Detected by cppcheck.
Signed-off-by: NKamil Dudka <kdudka@redhat.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>