typo fix in comment

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/hush.c b/shell/hush.c
index fc9b89b..912ecf1 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -1389,7 +1389,7 @@
  * are set to '' (ignore) are NOT reset to defaults. We do the same.
  *
  * Problem: the above approach makes it unwieldy to catch signals while
- * we are in read builtin, of while we read commands from stdin:
+ * we are in read builtin, or while we read commands from stdin:
  * masked signals are not visible!
  *
  * New implementation