dwarf_loader: Call dwarf_cu__delete() when aborting the load

Addressing these covscan report entry:

  Error: GCC_ANALYZER_WARNING (CWE-401):
  dwarves-1.21/dwarf_loader.c:2645:40: warning[-Wanalyzer-malloc-leak]: leak of 'dcu'
  # 2643|                                      filename);
  # 2644|                         if (cu == NULL || cu__set_common(cu, conf, mod, elf) != 0)
  # 2645|->                         	return DWARF_CB_ABORT;
  # 2646|
  # 2647|                         dcu = malloc(sizeof(struct dwarf_cu));

  Error: RESOURCE_LEAK (CWE-772):
  dwarves-1.21/dwarf_loader.c:2647: alloc_fn: Storage is returned from allocation function "malloc".
  dwarves-1.21/dwarf_loader.c:2647: var_assign: Assigning: "dcu" = storage returned from "malloc(120UL)".
  dwarves-1.21/dwarf_loader.c:2663: leaked_storage: Variable "dcu" going out of scope leaks the storage it points to.
  # 2661|                         }
  # 2662|                         if (hashtags__bits < default_hbits)
  # 2663|->                               return DWARF_CB_ABORT;
  # 2664|
  # 2665|                         dcu->cu = cu;

  Error: CLANG_WARNING:
  dwarves-1.21/dwarf_loader.c:2663:12: warning[unix.Malloc]: Potential leak of memory pointed to by 'dcu'
  # 2661|                         }
  # 2662|                         if (hashtags__bits < default_hbits)
  # 2663|->                               return DWARF_CB_ABORT;
  # 2664|
  # 2665|                         dcu->cu = cu;

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

dwarf_loader.c

@@ -2696,6 +2696,7 @@ static int cus__merge_and_process_cu(struct cus *cus, struct conf_load *conf,
 	return 0;
 
 out_abort:
+	dwarf_cu__delete(cu);
 	cu__delete(cu);
 	return DWARF_CB_ABORT;
 }