fix configure script

Author: mcarbonneaux

configure

@@ -3240,15 +3240,11 @@ $as_echo "$as_me: error: Specify where is the libmemcached directory using --wit
    { (exit 1); exit 1; }; }
   else
     ARCH=$(uname -m)
-    OS=$(uname -s | tr ':upper:' ':lower:')
-    if test -d "${with_libmemcached}/lib/${ARCH}-${OS}-gnu"; then
-      LIBDIR="lib/${ARCH}-${OS}-gnu"
-    else
-      LONG_BIT=$(getconf LONG_BIT)
-      if test "$LONG_BIT" -eq 64; then
+    LONG_BIT=$(getconf LONG_BIT)
+    LIBDIR=lib
+    if test "$LONG_BIT" -eq 64; then
+      if test -d $with_libmemcached/lib64; then
         LIBDIR=lib64
-      else
-        LIBDIR=lib
       fi
     fi
     LIBMEMCACHED_INCLUDE_DIR=$with_libmemcached/include