t9400: fix gnuism in grep

Using "\+" in "grep" and expecting that it means one or more
is a GNUism.  Spell it in a dumb and portable way.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t9400-git-cvsserver-server.sh

@@ -500,8 +500,8 @@ test_expect_success 'cvs status (no subdirs in header)' '
 cd "$WORKDIR"
 test_expect_success 'cvs co -c (shows module database)' '
     GIT_CONFIG="$git_config" cvs co -c > out &&
-    grep "^master[	 ]\+master$" < out &&
-    ! grep -v "^master[	 ]\+master$" < out
+    grep "^master[	 ][ 	]*master$" <out &&
+    ! grep -v "^master[	 ][ 	]*master$" <out
 '
 
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