RISC-V: Fix the static-PIE non-relocated object check

The value of l_scope is only valid post relocation, so this original
check was triggering undefined behavior.  Instead just directly check to
see if the object has been relocated, at which point using l_scope is
safe.

Reported-by: Andreas Schwab <schwab@suse.de>
Closes: BZ #31317
Fixes: e0590f41 ("RISC-V: Enable static-pie.")
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>