ia64 perfmon: fix get_unmapped_area() use there

get_unmapped_area() returns -E... on failure, not 0.  Moreover, the
wrapper around it is completely pointless.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/ia64/kernel/perfmon.c

@@ -604,12 +604,6 @@ pfm_unprotect_ctx_ctxsw(pfm_context_t *x, unsigned long f)
 	spin_unlock(&(x)->ctx_lock);
 }
 
-static inline unsigned long 
-pfm_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags, unsigned long exec)
-{
-	return get_unmapped_area(file, addr, len, pgoff, flags);
-}
-
 /* forward declaration */
 static const struct dentry_operations pfmfs_dentry_operations;
 
@@ -2333,8 +2327,8 @@ pfm_smpl_buffer_alloc(struct task_struct *task, struct file *filp, pfm_context_t
 	down_write(&task->mm->mmap_sem);
 
 	/* find some free area in address space, must have mmap sem held */
-	vma->vm_start = pfm_get_unmapped_area(NULL, 0, size, 0, MAP_PRIVATE|MAP_ANONYMOUS, 0);
-	if (vma->vm_start == 0UL) {
+	vma->vm_start = get_unmapped_area(NULL, 0, size, 0, MAP_PRIVATE|MAP_ANONYMOUS);
+	if (IS_ERR_VALUE(vma->vm_start)) {
 		DPRINT(("Cannot find unmapped area for size %ld\n", size));
 		up_write(&task->mm->mmap_sem);
 		goto error;