Change device to devices in find_root_devices_from_libzfs

Index: grub/util/getroot.c
===================================================================
--- grub.orig/util/getroot.c	2012-01-31 00:34:31.014033000 -0600
+++ grub/util/getroot.c	2012-01-31 00:36:16.026730000 -0600
@@ -512,7 +512,7 @@
 static char **
 find_root_devices_from_libzfs (const char *dir)
 {
-  char **device = NULL;
+  char **devices = NULL;
   char *poolname;
   char *poolfs;
 
@@ -520,13 +520,13 @@
   if (! poolname)
     return NULL;
 
-  device = find_root_devices_from_poolname (poolname);
+  devices = find_root_devices_from_poolname (poolname);
 
   free (poolname);
   if (poolfs)
     free (poolfs);
 
-  return device;
+  return devices;
 }
 
 #ifdef __MINGW32__