pgsql: Remove useless pg_strdup() operations.

Remove useless pg_strdup() operations.

split_to_stringlist() doesn't modify its first argument nor expect it
to remain valid after exit, so there's no need to duplicate the optarg
string at the call sites. Per Coverity. (This has been wrong all along,
but commit 052cc223d changed the useless calls from "strdup" to
"pg_strdup", which apparently made Coverity think it's a new bug.
It's not, but it's also not worth back-patching.)

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/a2d75b67bccd24d17e328360080e4877d23bc369

Modified Files
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src/test/regress/pg_regress.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)