Remove inline ASM for /% word.

Remove inline ASM for /% word.

This was used with the mspgcc in Ubuntu 12.04 LTS, the libc function
__divmodhi4 was unnecessarily called twice.  The updated mspgcc in
Ubuntu 14.04 LTS:
  "msp430-gcc (GCC) 4.6.3 20120301 (mspgcc LTS 20120406 unpatched)"
used from now has a (better?) libc and compilation of the libc.  Also,
__divmodhi4 is not present anyway in the new libc and therefore throws an
error.