mm/mremap: convert vma_adjust() to vma_expand()

Stop using vma_adjust() in preparation for removing the function.  Export
vma_expand() to use instead.

Link: https://lkml.kernel.org/r/20230120162650.984577-45-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/mm/mmap.c b/mm/mmap.c
index 3d08d7d..9599db0 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -634,9 +634,9 @@ static inline void vma_complete(struct vma_prepare *vp,
  *
  * Returns: 0 on success
  */
-inline int vma_expand(struct vma_iterator *vmi, struct vm_area_struct *vma,
-		      unsigned long start, unsigned long end, pgoff_t pgoff,
-		      struct vm_area_struct *next)
+int vma_expand(struct vma_iterator *vmi, struct vm_area_struct *vma,
+	       unsigned long start, unsigned long end, pgoff_t pgoff,
+	       struct vm_area_struct *next)
 {
 	bool remove_next = false;
 	struct vma_prepare vp;