cpufreq: interactive: fix compiling warnings
The gcc warns like:

  cpufreq_interactive.c:745:6: warning: operation on 'ret' may be
undefined [-Wsequence-point]

Since sprintf(...) just return 1 (one character) in this case, ret
should not changed.
Just discarding the result of sprintf(...) .

So this fix the build in Linaro GCC 4.9 or any other on GCC 4.9
Merge https://github.com/AnimeROM/android_kernel_motorola_msm8226 into HEAD