pgsql: plsample: Use TextDatumGetCString() for text-to-CString conversi

plsample: Use TextDatumGetCString() for text-to-CString conversion

Replace the outdated DatumGetCString(DirectFunctionCall1(textout, ...))
pattern with TextDatumGetCString(). The macro is the modern, more
efficient way to convert a text Datum to a C string as it avoids
unnecessary function call machinery and handles detoasting internally.

Since plsample serves as reference code for extension authors, it
should follow current idiomatic practices.

Author: Amul Sul <sulamul(at)gmail(dot)com>
Discussion: https://postgr.es/m/CAAJ_b95-xMvUN1PEqxv8y6g-A-8k+fSgyv20kSZc9eF1wZAUPg@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/f1cfb48efb086f99f6995f5d4b8a7c3ee289d1f0

Modified Files
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src/test/modules/plsample/plsample.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)