Added double quotes around a shell function argument.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@8579 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/drd/scripts/measurement-functions b/drd/scripts/measurement-functions
index f36b01f..dbbee6c 100644
--- a/drd/scripts/measurement-functions
+++ b/drd/scripts/measurement-functions
@@ -10,7 +10,7 @@
 
   for ((i=0;i<64;i++))
   do
-    if [ $((2**i)) = $1 ]; then
+    if [ $((2**i)) = "$1" ]; then
       echo $i
       return 0
     fi