rtla/timerlat: Fix "Previous IRQ" auto analysis' line

rtla/timerlat: Fix "Previous IRQ" auto analysis' line

The "Previous IRQ interference" line is misaligned and without
a \n, breaking the tool's output:

 ## CPU 12 hit stop tracing, analyzing it ##
  Previous IRQ interference:			up to      2.22 us  IRQ handler delay:		                	    18.06 us (0.00 %)
  IRQ latency:						    18.52 us
  Timerlat IRQ duration:				     4.41 us (0.00 %)
  Blocking thread:					   216.93 us (0.03 %)

Fix the output:

 ## CPU 7 hit stop tracing, analyzing it ##
  Previous IRQ interference:			 up to       8.93 us
  IRQ handler delay:		                	     0.98 us (0.00 %)
  IRQ latency:						     2.95 us
  Timerlat IRQ duration:				    11.26 us (0.03 %)

Link: https://lore.kernel.org/linux-trace-devel/8b5819077f15ccf24745c9bf3205451e16ee32d9.1679685525.git.bristot@kernel.org
Fixes: 27e348b221f6 ("rtla/timerlat: Add auto-analysis core")
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>