"load data infile .."  allowed for access to 
unautohorized tables.
Due to a faulty if-statement it was possible to
circumvent the secure_file_priv restriction.


mysql-test/mysql-test-run.pl:
  * Add SECURE_LOAD_PATH environment variable to mtr test cases.
mysql-test/suite/sys_vars/r/secure_file_priv2.result:
  * add test for bug58747
mysql-test/suite/sys_vars/t/secure_file_priv2-master.opt:
  * add test for bug58747
mysql-test/suite/sys_vars/t/secure_file_priv2.test:
  * add test for bug58747
sql/sql_load.cc:
  * Correct faulty if-statement
  * fix indentation
  * move my_stat() block to after is_secure_file_path() check.