riscv: Correct type casting in module loading

Use __le16 with le16_to_cpu.

Fixes: 8fd6c514 ("riscv: Add remaining module relocations")
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20231127-module_linking_freeing-v4-2-a2ca1d7027d0@rivosinc.com


Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>