ENGR00178118-1 fix some build warnings when using GCC 4.6.2

ENGR00178118-1 fix some build warnings when using GCC 4.6.2

fix some build warnings when using GCC 4.6.2:

drivers/cpufreq/cpufreq_interactive.c:127:6:
warning:'irq_count' may be used uninitialized in this function [-Wuninitialized]
drivers/media/video/mxc/output/mxc_vout.c:1346:5:
warning: 'ret' may be used uninitialized in this function [-Wuninitialized]
drivers/video/mxc/mxc_ipuv3_fb.c:1329:23:
warning: operation on 'mxc_fbi->cur_ipu_buf' may be undefined [-Wsequence-point]
drivers/video/mxc/mxc_ipuv3_fb.c:1376:24:
warning: operation on 'mxc_fbi->cur_ipu_buf' may be undefined [-Wsequence-point]
drivers/video/mxc/mxc_ipuv3_fb.c:1377:24:
warning: operation on 'mxc_fbi->cur_ipu_buf' may be undefined [-Wsequence-point]

Signed-off-by: Jason Liu <r64343@freescale.com>