mm/shmem: remove unneeded assignments in shmem_get_folio_gfp()

After the rework of shmem_get_folio_gfp() to use a folio, the local
variable hindex is only needed to be set once before passing it to
shmem_add_to_page_cache().

Remove the unneeded initialization and assignments of the variable hindex
before the actual effective assignment and first use.

No functional change. No change in object code.

Link: https://lkml.kernel.org/r/20221007085027.6309-1-lukas.bulwahn@gmail.comSigned-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/shmem.c

@@ -1826,7 +1826,7 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
 	struct shmem_sb_info *sbinfo;
 	struct mm_struct *charge_mm;
 	struct folio *folio;
-	pgoff_t hindex = index;
+	pgoff_t hindex;
 	gfp_t huge_gfp;
 	int error;
 	int once = 0;
@@ -1864,7 +1864,6 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
 	}
 
 	if (folio) {
-		hindex = folio->index;
 		if (sgp == SGP_WRITE)
 			folio_mark_accessed(folio);
 		if (folio_test_uptodate(folio))