ash: allow newline after variable name in for loop

Newline is a valid delimiter between the variable name and `in`
keyword in for loops.

Based on commit 22e8fb4 from git://git.kernel.org/pub/scm/utils/dash/dash.git
by Herbert Xu.

function                                             old     new   delta
parse_command                                       1568    1563      -5
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-5)               Total: -5 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/ash_test/ash-misc/for.right b/shell/ash_test/ash-misc/for.right
new file mode 100644
index 0000000..d86bac9
--- /dev/null
+++ b/shell/ash_test/ash-misc/for.right
@@ -0,0 +1 @@
+OK