typo fix in a comment in a testcase. oh well...

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/hush_test/hush-trap/subshell.tests b/shell/hush_test/hush-trap/subshell.tests
index b5d6094..4564c2e 100755
--- a/shell/hush_test/hush-trap/subshell.tests
+++ b/shell/hush_test/hush-trap/subshell.tests
@@ -11,7 +11,7 @@
 # With TERM we'll check whether it is reset
 trap 'bad: caught TERM'  TERM
 
-# using bash, becuase we don't have $PPID (yet)
+# using bash, because we don't have $PPID (yet)
 (bash -c 'kill -HUP   $PPID'; echo Ok)
 (bash -c 'kill -QUIT  $PPID'; echo Ok)
 (bash -c 'kill -SYS   $PPID'; echo Ok)