btrfs-progs: tests, use non-interactive sudo helper

Sudo may not be configured to run without user prompt, in that case the
tests would be stuck.

Reported-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>

tests/common

@@ -58,7 +58,7 @@ export have_root_helper
 setup_root_helper()
 {
 	if [ $UID != 0 ]; then
-		sudo=sudo
+		sudo="sudo --non-interactive"
 	fi
 	have_root_helper=1
 }