xpmem: Fix deadlock in xpmem_remove_process_memory_range()

This reverts commit 2fe5c8de2e.

Change-Id: I8ec84f654aeee7cf83603abb2aca5e90b735e977

test/xpmem/mc_run.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+
+test -e /tmp/xpmem.share && rm -f /tmp/xpmem.share
+test -e /tmp/xpmem.lock && rm -f /tmp/xpmem.lock
+
+# create TMP_SHARE_SIZE bytes defined in xpmem_test.h
+for i in `seq 0 31` ; do
+	echo -n 0 >> /tmp/xpmem.share
+done
+echo 0 > /tmp/xpmem.lock
+
+# Run the main test app
+mcexec $PWD/xpmem_master
+exit 0
+