pgsql-server: Fix a read of uninitialized memory in array_out().

Log Message:
-----------
Fix a read of uninitialized memory in array_out(). Perform some minor
cosmetic code cleanup at the same time.

Modified Files:
--------------
pgsql-server/src/backend/utils/adt:
arrayfuncs.c (r1.111 -> r1.112)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/utils/adt/arrayfuncs.c.diff?r1=1.111&r2=1.112)
arrayutils.c (r1.16 -> r1.17)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/utils/adt/arrayutils.c.diff?r1=1.16&r2=1.17)
pgsql-server/src/include/utils:
array.h (r1.49 -> r1.50)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/utils/array.h.diff?r1=1.49&r2=1.50)