RISC-V: PR32001, Untranslated "internal:" prefix for error message.

bfd/
	PR 32001
	* elfxx-riscv.c (riscv_update_subset1): Fixed the untranslated
	"internal:" prefix for error message.

bfd/elfxx-riscv.c

diff --git a/bfd/elfxx-riscv.c b/bfd/elfxx-riscv.c
index b3adbed..b8f314d 100644
--- a/bfd/elfxx-riscv.c
+++ b/bfd/elfxx-riscv.c
@@ -2386,7 +2386,7 @@
 		      const char *implicit_exts)
 {
   const char *p = implicit_exts;
-  const char *errmsg_internal = explicit_subset == NULL ? "" : "internal: ";
+  const char *errmsg_internal = explicit_subset == NULL ? "" : _("internal: ");
   const char *errmsg_caller = explicit_subset == NULL
 			      ? ".option arch" : "riscv_implicit_subsets";