util: remove unused variable

Variable became obsolete and was left in although unused.

Change-Id: I2953c1eea836fb96812a8834f1776aff16b76745
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/util.cpp b/util.cpp
index cf9ef81..1889256 100644
--- a/util.cpp
+++ b/util.cpp
@@ -27,8 +27,6 @@
 
 IOInterfaceType GetWriteInterfaceType(const std::string& path)
 {
-    std::string::size_type n;
-
     if (path.empty() || "None" == path)
     {
         return IOInterfaceType::NONE;
@@ -45,8 +43,6 @@
 
 IOInterfaceType GetReadInterfaceType(const std::string& path)
 {
-    std::string::size_type n;
-
     if (path.empty() || "None" == path)
     {
         return IOInterfaceType::NONE;