readlink(2) does not write a terminating NUL, and the read side
will already place a NUL after whatever it receives.
While it seems odd that this would be buggy (ie, synlinks on
the ohter side would be pointing to the wrong filename, though
I guess if we're lucky and the stack had a 0 byte at the right
place, symlink(2) would do what was expected), my reading of
the code tells me this patch is right. Needs testing to double
check.
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