pgsql: Return a value from Install.pm's lcopy function

Return a value from Install.pm's lcopy function

Commit 3a7cc727c was a little over eager about adding an explicit return
to this function, whose value is checked in most call sites. This change
reverses that and returns the expected value explicitly. It also adds a
check to the one call site lacking one.

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/01deec5f8ae64b5120cc8c93d54fe0e19e477b02

Modified Files
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src/tools/msvc/Install.pm | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)