pgsql: Fix error reporting after ioctl() call with pg_upgrade --clone

Fix error reporting after ioctl() call with pg_upgrade --clone

errno was not reported correctly after attempting to clone a file,
leading to incorrect error reports. While scanning through the code, I
have not noticed any similar mistakes.

Error introduced in 3a769d8.

Author: Justin Pryzby
Discussion: /messages/by-id/20220731134135.GY15006@telsasoft.com
Backpatch-through: 12

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/8b1ec7d2953273501c5cea8185b6358dc7709eb5

Modified Files
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src/bin/pg_upgrade/file.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)