ldelf: riscv: e64_relocate(): tag sym_idx as __maybe_unused

The sym_idx variable in e64_relocate() is not used in the rv64 build.
Therefore, mark it __maybe_unused to avoid a warning.

Signed-off-by: Jerome Forissier <[email protected]>
Reviewed-by: Etienne Carriere <[email protected]>
Reviewed-by: Alvin Chang <[email protected]>
Acked-by: Jens Wiklander <[email protected]>

ldelf/ta_elf_rel.c

@@ -644,7 +644,7 @@ static void e64_relocate(struct ta_elf *elf, unsigned int rel_sidx)
 	rela_end = rela + shdr[rel_sidx].sh_size / sizeof(Elf64_Rela);
 	for (; rela < rela_end; rela++) {
 		Elf64_Addr *where = NULL;
-		size_t sym_idx = 0;
+		size_t sym_idx __maybe_unused = 0;
 
 		/* Check the address is inside TA memory */
 		if (rela->r_offset >= (elf->max_addr - elf->load_addr))