Fixed test_db_env_set_errpfx

git-svn-id: file:///svn/tokudb@687 c7de825b-a66e-492c-adef-691d508d4ae1

src/tests/test_db_env_set_errpfx.c

 #include <stdio.h>
 #include <assert.h>
 #include <db.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 
 // DIR is defined in the Makefile
 
@@ -8,6 +11,9 @@ int main() {
     DB_ENV *dbenv;
     int r;
 
+    system("rm -rf " DIR);
+    mkdir(DIR, 0777);
+
     r = db_env_create(&dbenv, 0);
     assert(r == 0);
 
@@ -16,6 +22,8 @@ int main() {
     r = dbenv->open(dbenv, DIR, DB_CREATE|DB_PRIVATE|DB_INIT_MPOOL, 0);
     assert(r == 0);
 
+    dbenv->set_errpfx(dbenv, "houdy partners: ");
+
     r = dbenv->close(dbenv, 0);
     assert(r == 0);