kmem.sh: fix typo so -D works

Change-Id: I3571bb650c92f48ca37f9512de364df549cc1f96

kmem.sh

diff --git a/kmem.sh b/kmem.sh
index 0bba9c3..f8609a1 100755
--- a/kmem.sh
+++ b/kmem.sh
@@ -68,7 +68,7 @@
                 ;;
 
             -D|--debug)
-                BUILD="wdebug"
+                BUILD="debug"
                 shift
                 ;;