rtla: Remove unused headers

Remove unused includes for <errno.h> and <signal.h> to clean up the
code and reduce unnecessary dependencies.

Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Link: https://lore.kernel.org/r/20260106133655.249887-12-wander@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>

Author: walac

tools/tracing/rtla/src/osnoise_hist.c

@@ -9,7 +9,6 @@
 #include <string.h>
 #include <signal.h>
 #include <unistd.h>
-#include <errno.h>
 #include <stdio.h>
 #include <time.h>
 

tools/tracing/rtla/src/timerlat.c

@@ -9,7 +9,6 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
-#include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
 #include <sched.h>

tools/tracing/rtla/src/timerlat_top.c

@@ -11,7 +11,6 @@
 #include <unistd.h>
 #include <stdio.h>
 #include <time.h>
-#include <errno.h>
 #include <sched.h>
 #include <pthread.h>
 

tools/tracing/rtla/src/trace.c

@@ -2,7 +2,6 @@
 #define _GNU_SOURCE
 #include <sys/sendfile.h>
 #include <tracefs.h>
-#include <signal.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <errno.h>