riscv: Move create_tmp_mapping() to init sections

riscv: Move create_tmp_mapping() to init sections

commit 9bdd924803787ceeb10f1ea399e91d75fb05d3a7 upstream.

This function is only used at boot time so mark it as __init.

Fixes: 96f9d4daf745 ("riscv: Rework kasan population functions")
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230704074357.233982-2-alexghiti@rivosinc.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>