selftests/timens: Make run_tests() functions static

These functions are never used outside their defining compilation unit and
can be made static.

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Thomas Weißschuh <[e-mail]>
Reviewed-by: Muhammad Usama Anjum <[e-mail]>
Signed-off-by: Shuah Khan <[e-mail]>

tools/testing/selftests/timens/clock_nanosleep.c

···
 	return NULL;
 }
 
-int run_test(int clockid, int abs)
+static int run_test(int clockid, int abs)
 {
 	struct timespec now = {}, rem;
 	struct thread_args args = { .now = &now, .rem = &rem, .clockid = clockid};

tools/testing/selftests/timens/timer.c

···
 #include "log.h"
 #include "timens.h"
 
-int run_test(int clockid, struct timespec now)
+static int run_test(int clockid, struct timespec now)
 {
 	struct itimerspec new_value;
 	long long elapsed;

tools/testing/selftests/timens/timerfd.c

···
 	return clock_gettime(clockid, now);
 }
 
-int run_test(int clockid, struct timespec now)
+static int run_test(int clockid, struct timespec now)
 {
 	struct itimerspec new_value;
 	long long elapsed;