update dynamic_load_error to compare error message only

Summary:
dynamic_load_error testcase simulate error during dynamic load wsenv library.

Sometime dynamic_load_error MTR will fail due to different errno: 11(EAGAIN),
```
-ERROR HY000: Can't open shared library 'librocks_object_factory.so' (errno: 0 (null))
+ERROR HY000: Can't open shared library 'librocks_object_factory.so' (errno: 11 (null))
```

update testcase to compare "Can't open shared library" only.

Reviewed By: lth

Differential Revision: D37026294

fbshipit-source-id: 5d466340a200c1a5238fb4ee02155b24f77590b6

Author: luqun

mysql-test/suite/sql_wsenv/r/dynamic_load_error_wsenv.result

@@ -2,7 +2,7 @@ set enable_sql_wsenv=1;
 CREATE TABLE t1(x VARCHAR(100));
 SET SESSION debug='d,simulate_wsenv_dlopen_error';
 SELECT * FROM t1 INTO OUTFILE 'OUTPUT_FILE';;
-ERROR HY000: Can't open shared library 'librocks_object_factory.so' (errno: 0 (null))
+ERROR HY000: Can't open shared library
 SET SESSION debug=DEFAULT;
 SELECT * FROM t1 INTO OUTFILE 'OUTPUT_FILE';;
 ERROR HY000: Can't create/write to file 'OUTPUT_FILE' (OS errno 22 - Invalid argument)

mysql-test/suite/sql_wsenv/t/dynamic_load_error_wsenv.test

@@ -7,6 +7,7 @@ CREATE TABLE t1(x VARCHAR(100));
 SET SESSION debug='d,simulate_wsenv_dlopen_error';
 --let $output_file=$SQL_WSENV_MTR_PATH/t1.txt
 --replace_result $output_file OUTPUT_FILE
+--replace_regex /.*Can\'t open shared library.*/Can't open shared library/
 --error 92
 --eval SELECT * FROM t1 INTO OUTFILE '$output_file';
 SET SESSION debug=DEFAULT;