fix saving and loading mission file on tablet

src/MissionEditor/MissionEditor.qml

@@ -246,7 +246,7 @@ QGCView {
         QGCMobileFileDialog {
             openDialog:         true
             fileExtension:      _syncDropDownController.fileExtension
-            onFilenameReturned: _syncDropDownController.loadFromfile(filename)
+            onFilenameReturned: _syncDropDownController.loadFromFile(filename)
         }
     }
 
@@ -256,7 +256,7 @@ QGCView {
         QGCMobileFileDialog {
             openDialog:         false
             fileExtension:      _syncDropDownController.fileExtension
-            onFilenameReturned: _syncDropDownController.saveToFile()
+            onFilenameReturned: _syncDropDownController.saveToFile(filename)
         }
     }