bfd: aarch64: Fix leaks in case of BTI stub reuse

BTI stub parameters were recomputed even if those were already set up.
This is unnecessary work and leaks the symbol name that is allocated
for the stub.
diff --git a/bfd/elfnn-aarch64.c b/bfd/elfnn-aarch64.c
index 798643a..3adece3 100644
--- a/bfd/elfnn-aarch64.c
+++ b/bfd/elfnn-aarch64.c
@@ -4665,33 +4665,41 @@
 		  stub_entry_bti =
 		    aarch64_stub_hash_lookup (&htab->stub_hash_table,
 					      stub_name_bti, false, false);
-		  if (stub_entry_bti == NULL)
-		    stub_entry_bti =
-		      _bfd_aarch64_add_stub_entry_in_group (stub_name_bti,
-							    sym_sec, htab);
-		  if (stub_entry_bti == NULL)
+		  if (stub_entry_bti != NULL)
+		    BFD_ASSERT (stub_entry_bti->stub_type
+				== aarch64_stub_bti_direct_branch);
+		  else
 		    {
-		      free (stub_name);
-		      free (stub_name_bti);
-		      goto error_ret_free_internal;
-		    }
+		      stub_entry_bti =
+			_bfd_aarch64_add_stub_entry_in_group (stub_name_bti,
+							      sym_sec, htab);
+		      if (stub_entry_bti == NULL)
+			{
+			  free (stub_name);
+			  free (stub_name_bti);
+			  goto error_ret_free_internal;
+			}
 
-		  stub_entry_bti->target_value = sym_value + irela->r_addend;
-		  stub_entry_bti->target_section = sym_sec;
-		  stub_entry_bti->stub_type = aarch64_stub_bti_direct_branch;
-		  stub_entry_bti->h = hash;
-		  stub_entry_bti->st_type = st_type;
+		      stub_entry_bti->target_value =
+			sym_value + irela->r_addend;
+		      stub_entry_bti->target_section = sym_sec;
+		      stub_entry_bti->stub_type =
+			aarch64_stub_bti_direct_branch;
+		      stub_entry_bti->h = hash;
+		      stub_entry_bti->st_type = st_type;
 
-		  len = sizeof (BTI_STUB_ENTRY_NAME) + strlen (sym_name);
-		  stub_entry_bti->output_name = bfd_alloc (htab->stub_bfd, len);
-		  if (stub_entry_bti->output_name == NULL)
-		    {
-		      free (stub_name);
-		      free (stub_name_bti);
-		      goto error_ret_free_internal;
+		      len = sizeof (BTI_STUB_ENTRY_NAME) + strlen (sym_name);
+		      stub_entry_bti->output_name = bfd_alloc (htab->stub_bfd,
+							       len);
+		      if (stub_entry_bti->output_name == NULL)
+			{
+			  free (stub_name);
+			  free (stub_name_bti);
+			  goto error_ret_free_internal;
+			}
+		      snprintf (stub_entry_bti->output_name, len,
+				BTI_STUB_ENTRY_NAME, sym_name);
 		    }
-		  snprintf (stub_entry_bti->output_name, len,
-			    BTI_STUB_ENTRY_NAME, sym_name);
 
 		  /* Update the indirect call stub to target the BTI stub.  */
 		  stub_entry->target_value = 0;