Fix minor grammar mistake in the help output

Change "quick" to quicker, so the help message reads
-c    --check               Stop if lower prio task is quicker than
higher (off)

Signed-off-by: John Kacur <jkacur@redhat.com>
diff --git a/src/rt-migrate-test/rt-migrate-test.c b/src/rt-migrate-test/rt-migrate-test.c
index 67e1e6c..fc6fd81 100644
--- a/src/rt-migrate-test/rt-migrate-test.c
+++ b/src/rt-migrate-test/rt-migrate-test.c
@@ -186,7 +186,7 @@
 	       "-s time --sleep-time time   Sleep time (ms) between intervals (100)\n"
 	       "-m time --maxerr time       Max allowed error (microsecs)\n"
 	       "-l loops --loops loops      Number of iterations to run (50)\n"
-	       "-c    --check               Stop if lower prio task is quick than higher (off)\n"
+	       "-c    --check               Stop if lower prio task is quicker than higher (off)\n"
 	       "  () above are defaults \n",
 		p);
 	exit(0);