Drop an unused variable.

Index: grub/util/getroot.c
===================================================================
--- grub.orig/util/getroot.c	2012-01-31 00:50:08.674484255 -0600
+++ grub/util/getroot.c	2012-01-31 00:50:24.200438000 -0600
@@ -293,7 +293,6 @@
 		&& !sscanf (name, "raidz%u", &dummy)
 		&& !strcmp (state, "ONLINE"))
 	      {
-		char *tmp;
 		if (ndevices >= devices_allocated)
 		  {
 		    devices_allocated = 2 * (devices_allocated + 8);