Description: starting server with options --general-log --general-log-file=
fails and causes core dump.

Analysis: When user specifies the option like "slow_query_log_file=" or
"general_log_file=" in the conf file without specifying the file name it
causes an invalid memory free.
opt_logname/opt_slow_logname will point to argv in case of empty string.
And we are trying to free that memory address. Which causes the invalid
memory free error.
Since the empty string belongs to
argv "my_free" call is not required. Hence removed.