Small fix to image info

Use default storage if user does not specify, so it doesn't output
"Unable to associate string 'None' with backend".

Signed-off-by: Yu Qi Zhang <jerzhang@redhat.com>

Closes: #933
Approved by: baude

Atomic/info.py

@@ -113,7 +113,7 @@ class Info(Atomic):
 
         if self.args.force:
             # The user wants information on a remote image
-            be = self.beu.get_backend_from_string(self.args.storage)
+            be = self.beu.get_backend_from_string(str_backend=self.args.storage or storage)
             img_obj = be.make_remote_image(self.image)
         else:
             # The image is local

bash/atomic

@@ -190,6 +190,7 @@ _atomic_images_info() {
 	"
 	local all_options="$options_with_args
 		-h --help
+		--remote
 	"
 
 	case "$prev" in