More exit handling fixes

Summary:
Line 166 is missing a process.exit() causing the process to stay open forever if anything goes wrong.

Making everything use errorAndExit, and making use of the utility function so we don't need to remember when to print e, and when to print e.message.

Reviewed By: passy

Differential Revision: D15989164

fbshipit-source-id: c683fa07d98fe49283a59b5f8108ef54babc97a3

src/utils/exportData.js

@@ -290,11 +290,11 @@ export function exportStore(
       const {exportData, errorArray} = await getStoreExport(store);
       if (!exportData) {
         console.error('Make sure a device is connected');
-        reject('No device is selected');
+        reject(new Error('No device is selected'));
       }
       const serializedString = serialize(exportData);
       if (serializedString.length <= 0) {
-        reject('Serialize function returned empty string');
+        reject(new Error('Serialize function returned empty string'));
       }
       resolve({serializedString, errorArray});
     } catch (e) {