guests/debian: don't return from block [GH-3283]

CHANGELOG.md

@@ -10,6 +10,7 @@ BUG FIXES:
   - core: Vagrant won't collide with newer versions of Bundler [GH-3193]
   - core: Allow provisioner plugins to not have a config class. [GH-3272]
   - commands/status: Machine readable output contains the target. [GH-3218]
+  - guests/debian: Changing host name works properly. [GH-3283]
   - synced\_folders/smb: IDs of synced folders are hashed to work better
       with VMware. [GH-3219]
   - synced\_folders/smb: Passwords with symbols now work. [GH-3242]

plugins/guests/debian/cap/change_host_name.rb

@@ -32,10 +32,12 @@ module VagrantPlugins
         end
 
         def get_current_hostname
+          hostname = ""
           sudo "hostname -f" do |type, data|
-            return data.chomp if type == :stdout
+            hostname = data.chomp if type == :stdout && hostname.empty?
           end
-          ''
+
+          hostname
         end
 
         def update_etc_hostname