riscv: Fix early alternative patching

Now that the text to patch is located using a relative offset from the
alternative entry, the text address should be computed without applying
the kernel mapping offset, both before and after VM setup.

Fixes: 8d23e94a ("riscv: switch to relative alternative entries")
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Jisheng Zhang <jszhang@kernel.org>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230212021534.59121-2-samuel@sholland.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

arch/riscv/errata/thead/errata.c

@@ -102,9 +102,7 @@ void __init_or_module thead_errata_patch_func(struct alt_entry *begin, struct al
 
 			/* On vm-alternatives, the mmu isn't running yet */
 			if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
-				memcpy((void *)__pa_symbol(oldptr),
-				       (void *)__pa_symbol(altptr),
-				       alt->alt_len);
+				memcpy(oldptr, altptr, alt->alt_len);
 			else
 				patch_text_nosync(oldptr, altptr, alt->alt_len);
 		}