make ftrace_histogram.ko more readable

Also add verbose printf for table resize

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
rename ftrace_histogram.kp to function_profiler.kp

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
typo fix

scripts/funtion_time.kp -> scripts/function_time.kp

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>