gdb/dwarf: remove unused local variable in create_debug_type_hash_table

Change-Id: I40679fbe32a8a1a9cced085532c83f06affc294c
Approved-By: Tom Tromey <tom@tromey.com>

gdb/dwarf2/read.c

diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index b727471..5f64b05 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -2574,7 +2574,6 @@ create_debug_type_hash_table (dwarf2_per_objfile *per_objfile,
   end_ptr = info_ptr + section->size;
   while (info_ptr < end_ptr)
     {
-      signatured_type_up sig_type;
       struct dwo_unit *dwo_tu;
       void **slot;
       const gdb_byte *ptr = info_ptr;