The root cause of this defect is that a call to my_error() is using a
'LEX_STRING' parameter instead of a 'char*'

This patch fixes the failing calls to my_error(), as well as similar calls
found during investigation.

This is a compiling bug (see the instrumentation in the bug report), no test cases provided.


sql/sql_base.cc:
  Fix broken calls to "..." (va_args) functions.
sql/sql_table.cc:
  Fix broken calls to "..." (va_args) functions.