selftests: watchdog: fix spelling mistake "experies" -> "expires"

There is a spelling mistake in the --gettimeleft help text, fix it.

Signed-off-by: Colin Ian King <[e-mail]>
Signed-off-by: Shuah Khan <[e-mail]>

tools/testing/selftests/watchdog/watchdog-test.c

···
 	printf(" -T, --gettimeout    Get the timeout\n");
 	printf(" -n, --pretimeout=T  Set the pretimeout to T seconds\n");
 	printf(" -N, --getpretimeout Get the pretimeout\n");
-	printf(" -L, --gettimeleft   Get the time left until timer experies\n");
+	printf(" -L, --gettimeleft   Get the time left until timer expires\n");
 	printf("\n");
 	printf("Parameters are parsed left-to-right in real-time.\n");
 	printf("Example: %s -d -t 10 -p 5 -e\n", progname);