pgsql: plpgsql: Rename a variable for clarity

plpgsql: Rename a variable for clarity

Rename "core_yy_extra_type core_yy" to "core_yy_extra".  The previous
name was a bit unclear and confusing.  The new name matches the name
used elsewhere for the same purpose, for example in
src/backend/parser/gramparse.h.

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/3f2d72b4934945da76f6bc60dfe3fc5ca42e7526

Modified Files
--------------
src/pl/plpgsql/src/pl_scanner.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)