Tests: Redirect 'TEST' errors when it is expecting errors

Change-Id: Iad2535eca7a58526d1a23cea9b7cf445a3846782
BUG: 764966
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/4329
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>

tests/include.rc

@@ -83,10 +83,15 @@ function _TEST()
 {
 	TESTLINE=$1;
 	shift;
+        local redirect=""
 
 	test_header "$@";
 
-	eval "$@" >/dev/null 2>&1
+        if [ "$1"="!" ]; then
+                redirect="2>&1"
+        fi
+
+	eval "$@" >/dev/null $redirect
 
 	test_footer;
 }