moxaXmitBuff is almost unused -- only one byte from the whole PAGE_SIZE bytes
is used.  Do not alloc so much space for almost anything.  Also remove lock
protecting this page allocation.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>