itimer: Fix the itimer trace print format

Compiling powerpc64 results in:

include/trace/events/timer.h:279: warning:
format '%lu' expects type 'long unsigned int', but argument 4 has type 'cputime_t'
....

cputime_t on power is u64, which triggers the above warning.

Cast the cputime_t to unsigned long long and fix the print format
string. That works on both 32 and 64 bit architectures.

While at it change the print format for long variables from %lu to %ld.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>