Defining memscan() as memchr() is wrong, because the return values of
memscan() and memchr() are different when the character is not found.  So
use the generic memscan() implementation to fix this.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>