linux-user/elfload: Open core file after vma_init

Swap the ordering of vma_init and open.  This will be necessary
for further changes, and adjusts the error cleanup path.  Narrow
the scope of corefile, as the variable can be freed immediately
after use in open().

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

linux-user/elfload.c

@@ -4625,7 +4625,6 @@ static int elf_core_dump(int signr, const CPUArchState *env)
     const CPUState *cpu = env_cpu((CPUArchState *)env);
     const TaskState *ts = (const TaskState *)cpu->opaque;
     struct vm_area_struct *vma = NULL;
-    g_autofree char *corefile = NULL;
     struct elf_note_info info;
     struct elfhdr elf;
     struct elf_phdr phdr;
@@ -4644,19 +4643,22 @@ static int elf_core_dump(int signr, const CPUArchState *env)
         return 0;
     }
 
-    corefile = core_dump_filename(ts);
-
-    if ((fd = open(corefile, O_WRONLY | O_CREAT,
-                   S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH)) < 0)
-        return (-errno);
-
     /*
      * Walk through target process memory mappings and
      * set up structure containing this information.  After
      * this point vma_xxx functions can be used.
      */
     vma_init(&mm);
 
+    {
+        g_autofree char *corefile = core_dump_filename(ts);
+        fd = open(corefile, O_WRONLY | O_CREAT,
+                  S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
+    }
+    if (fd < 0) {
+        goto out;
+    }
+
     walk_memory_regions(&mm, vma_walker);
     segs = vma_get_mapping_count(&mm);