pgsql: Fix unchecked return value from strdup

Fix unchecked return value from strdup

The pg_dump compression was using strdup() instead of pg_strdup()
and failed to check the returned pointer for out-of-memory before
dereferencing it. Fix by using pg_strdup() instead which probably
was the intention here in the original patch.

Backpatch to v16 where pg_dump compression was introduced.

Reviewed-by: Tristan Partin <tristan(at)neon(dot)tech>
Reviewed-by: Nathan Bossart <nathandbossart(at)gmail(dot)com>
Discussion: https://postgr.es/m/CC661D60-6F4C-474D-B9CF-E789ACA3CEFC@yesql.se
Backpatch-through: 16

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/30e54d5c5d8fceb7287162c116961fa0627544f5

Modified Files
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src/bin/pg_dump/compress_io.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)