agetty: fix -s option (baud rate setup)

agetty: fix -s option (baud rate setup)

The problem is pretty visible in strace output:

broken version:
  ioctl(0, SNDCTL_TMR_TIMEBASE or TCGETS, {B115200 opost isig icanon echo ...}) = 0
  [...]
  ioctl(0, SNDCTL_TMR_START or TCSETS, {B0 -opost -isig -icanon -echo ...}) = 0
                                       ^^^
fixed version:
  ioctl(0, SNDCTL_TMR_TIMEBASE or TCGETS, {B115200 opost isig icanon echo ...}) = 0
  [...]
  ioctl(0, SNDCTL_TMR_START or TCSETS, {B115200 -opost -isig -icanon -echo ...}) = 0

Reported-by: Jon Masters <jcm@redhat.com>
Addresses: http://bugzilla.redhat.com/show_bug.cgi?id=645640
Signed-off-by: Karel Zak <kzak@redhat.com>