Fixed compiler warnings.

In set_var.cc, the code was not properly returning an error code
if close_cached_tables() failed.

In sql_tables.cc, the code was not returning properly an error code
if lock_table_names() failed.

Both cases are bugs, introduced in 5.1 only by recent changes.

into  weblab.(none):/home/marcsql/TREE/mysql-5.1-merge2

into  bodhi.local:/opt/local/work/mysql-5.1-runtime

into  weblab.(none):/home/marcsql/TREE/mysql-5.0-runtime

into  weblab.(none):/home/marcsql/TREE/mysql-5.0-19194

  limitation)
Bug#24854 (Mixing Searched Case with Simple Case inside Stored Procedure
  crashes Mysqld)

Implemented code review (19194) comments

into  example.com:/work/mysql-5.1-maint

into  neptunus.(none):/home/msvensson/mysql/mysql-5.1-maint

Remove DBUG_ENTER in my_end

uninitialized list of guarded instances.

into  neptunus.(none):/home/msvensson/mysql/mysql-5.1-maint

into  neptunus.(none):/home/msvensson/mysql/mysql-5.0-maint

into  neptunus.(none):/home/msvensson/mysql/mysql-5.1-maint

into  neptunus.(none):/home/msvensson/mysql/mysql-5.0-maint

into  neptunus.(none):/home/msvensson/mysql/mysql-4.1-maint

into  neptunus.(none):/home/msvensson/mysql/mysql-5.1-maint

into  neptunus.(none):/home/msvensson/mysql/mysql-5.1

into  rolltop.ignatz42.dyndns.org:/mnt/storeage/mysql-5.0-maint

into  rolltop.ignatz42.dyndns.org:/mnt/storeage/mysql-5.1-maint

into  rolltop.ignatz42.dyndns.org:/mnt/storeage/bug20836/my51-bug20836

into  rolltop.ignatz42.dyndns.org:/mnt/storeage/bug20836/my50-bug20836

- Comment Cleanup.

error message in the logs before shutting down the server

into  neptunus.(none):/home/msvensson/mysql/mysql-5.0-maint

into  neptunus.(none):/home/msvensson/mysql/mysql-5.1-maint

into  kahlann.erinye.com:/home/df/mysql/build/mysql-5.1-build

into  kahlann.erinye.com:/home/df/mysql/build/mysql-5.0-build-work