fs/exec.c:__bprm_mm_init(): clean up error handling

Untangle the error unwinding in this function, saving a test of local
variable `vma'.
Signed-off-by: Luiz Fernando N. Capitulino <lcapitulino@mandriva.com.br>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/exec.c

@@ -232,13 +232,13 @@ static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos,
 
 static int __bprm_mm_init(struct linux_binprm *bprm)
 {
-	int err = -ENOMEM;
+	int err;
 	struct vm_area_struct *vma = NULL;
 	struct mm_struct *mm = bprm->mm;
 
 	bprm->vma = vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
 	if (!vma)
-		goto err;
+		return -ENOMEM;
 
 	down_write(&mm->mmap_sem);
 	vma->vm_mm = mm;
@@ -251,28 +251,20 @@ static int __bprm_mm_init(struct linux_binprm *bprm)
 	 */
 	vma->vm_end = STACK_TOP_MAX;
 	vma->vm_start = vma->vm_end - PAGE_SIZE;
-
 	vma->vm_flags = VM_STACK_FLAGS;
 	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
 	err = insert_vm_struct(mm, vma);
-	if (err) {
-		up_write(&mm->mmap_sem);
+	if (err)
 		goto err;
-	}
 
 	mm->stack_vm = mm->total_vm = 1;
 	up_write(&mm->mmap_sem);
-
 	bprm->p = vma->vm_end - sizeof(void *);
-
 	return 0;
-
 err:
-	if (vma) {
-		bprm->vma = NULL;
-		kmem_cache_free(vm_area_cachep, vma);
-	}
-
+	up_write(&mm->mmap_sem);
+	bprm->vma = NULL;
+	kmem_cache_free(vm_area_cachep, vma);
 	return err;
 }