onenand_spl_simple: Call onenand_spl_get_geometry() only once

Do not call onenand_spl_get_geometry() for each block read.

Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
diff --git a/drivers/mtd/onenand/onenand_spl.c b/drivers/mtd/onenand/onenand_spl.c
index 1925f41..6fad34a 100644
--- a/drivers/mtd/onenand/onenand_spl.c
+++ b/drivers/mtd/onenand/onenand_spl.c
@@ -110,9 +110,12 @@
  */
 int onenand_spl_read_block(int block, int offset, int len, void *dst)
 {
-	int page, read, psize;
+	int page, read;
+	static int psize;
+
+	if (!psize)
+		psize = onenand_spl_get_geometry();
 
-	psize = onenand_spl_get_geometry();
 	/* Calculate the page number */
 	page = offset / psize;
 	/* Offset to the start of a flash page */