Fix spelling; minor code cleanup.
diff --git a/common/cmd_nand.c b/common/cmd_nand.c
index fdbe7c7..7042a9c 100644
--- a/common/cmd_nand.c
+++ b/common/cmd_nand.c
@@ -251,7 +251,7 @@
 			       "Use this command only for testing purposes "
 			       "if you\n"
 			       "	 "
-			       "are shure of what you are doing!\n"
+			       "are sure of what you are doing!\n"
 			       "\nReally scrub this NAND flash? <y/N>\n"
 				);