tracing: Have show_event_trigger/filter format a bit more in columns

tracing: Have show_event_trigger/filter format a bit more in columns

By doing:

 # trace-cmd sqlhist -e -n futex_wait select TIMESTAMP_DELTA_USECS as lat from sys_enter_futex as start join sys_exit_futex as end on start.common_pid = end.common_pid

and

 # trace-cmd start -e futex_wait -f 'lat > 100' -e page_pool_state_release -f 'pfn == 1'

The output of the show_event_trigger and show_event_filter files are well
aligned because of the inconsistent 'tab' spacing:

 ~# cat /sys/kernel/tracing/show_event_triggers
syscalls:sys_exit_futex	hist:keys=common_pid:vals=hitcount:__lat_12046_2=common_timestamp.usecs-$__arg_12046_1:sort=hitcount:size=2048:clock=global:onmatch(syscalls.sys_enter_futex).trace(futex_wait,$__lat_12046_2) [active]
syscalls:sys_enter_futex	hist:keys=common_pid:vals=hitcount:__arg_12046_1=common_timestamp.usecs:sort=hitcount:size=2048:clock=global [active]

 ~# cat /sys/kernel/tracing/show_event_filters
synthetic:futex_wait	(lat > 100)
page_pool:page_pool_state_release	(pfn == 1)

This makes it not so easy to read. Instead, force the spacing to be at
least 32 bytes from the beginning (one space if the system:event is longer
than 30 bytes):

 ~# cat /sys/kernel/tracing/show_event_triggers
syscalls:sys_exit_futex          hist:keys=common_pid:vals=hitcount:__lat_8125_2=common_timestamp.usecs-$__arg_8125_1:sort=hitcount:size=2048:clock=global:onmatch(syscalls.sys_enter_futex).trace(futex_wait,$__lat_8125_2) [active]
syscalls:sys_enter_futex         hist:keys=common_pid:vals=hitcount:__arg_8125_1=common_timestamp.usecs:sort=hitcount:size=2048:clock=global [active]

 ~# cat /sys/kernel/tracing/show_event_filters
synthetic:futex_wait             (lat > 100)
page_pool:page_pool_state_release (pfn == 1)

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20260112153408.18373e73@gandalf.local.home
Reviewed-by: Aaron Tomlin <atomlin@atomlin.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>