[perl #78488] Bleadperl 304474c3 breaks GFUJI/Test-LeakTrace-0.13.tar.gz

[perl #78488] Bleadperl 304474c3 breaks GFUJI/Test-LeakTrace-0.13.tar.gz

This commit restores an SvREFCNT_dec that was inadvertently removed.

c8bbf67 removed the SvREFCNT_dec(HeVAL(entry)), adding
SvREFCNT_dec(old_val) instead.

304474c3 reverted that block, but failed to restore the
SvREFCNT_dec(HeVAL(entry)).

The result was that the %INC entry created by do "file" was leaking.

(Y’know, giving out commit bits to just *anyone* who comes along
with a few patches seems dangerous. Has anybody been looking at what
I’m doing?)