perf tools: Misc small fixes

perf tools: Misc small fixes

- util/header.c
	"len" is aligned to 64. So, it tries to write the out of
	long_name buffer.

	So, this use "zero_buf" to write aligned area.

- util/trace-event-read.c
	"size" is not including nul byte. So, this allocates it, and set '\0'.

- util/trace-event-parse.c
	It needs parens to calc correct size.

Signed-off-by: OGAWA Hirofumi <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>