Build warnings introduced by userstat.patch

[Alexey Kopytov]

Reporting the userstat.patch warnings as a separate bug per Yasufumi's request.

The following warnings are introduced by the patch when building on any non-Linux platform:

sql_parse.cc: In function ‘void mysql_parse(THD*, char*, uint, const char**)’:
sql_parse.cc:6142: warning: unused variable ‘tp’

sql_prepare.cc: In function ‘void mysqld_stmt_prepare(THD*, const char*, uint)’:
sql_prepare.cc:2116: warning: unused variable ‘tp’
sql_prepare.cc: In function ‘void mysqld_stmt_execute(THD*, char*, uint)’:
sql_prepare.cc:2564: warning: unused variable ‘tp’
sql_prepare.cc: In function ‘void mysqld_stmt_fetch(THD*, char*, uint)’:
sql_prepare.cc:2726: warning: unused variable ‘tp’
sql_prepare.cc: In function ‘void mysqld_stmt_reset(THD*, char*)’:
sql_prepare.cc:2855: warning: unused variable ‘tp’

[Yasufumi Kinoshita (yasufumi-kinoshita)]

I will fix also for 5.5.x soon

[Alexey Kopytov (akopytov)]

This bug was fixed only in 5.1, but not in 5.5 (so it also made it to 5.6).

It is a bit mysterious how I didn't notice it earlier. I'm fairly sure I could build both 5.5 and 5.6 in debug configuration and maintainer mode enabled until recently. It now fails for me with exactly the same symptoms, though the build environment seems to be the same.