typo fix

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/coreutils/tee.c b/coreutils/tee.c
index 2e1e367..e66e885 100644
--- a/coreutils/tee.c
+++ b/coreutils/tee.c
@@ -42,7 +42,7 @@
 	 * that doesn't consume all its input.  Good idea... */
 	signal(SIGPIPE, SIG_IGN);
 
-	/* Allocate an array of FILE *'s, with one extra for a sentinal. */
+	/* Allocate an array of FILE *'s, with one extra for a sentinel. */
 	fp = files = xzalloc(sizeof(FILE *) * (argc + 2));
 	np = names = argv - 1;