mtd: Bug in m25p80.c during whole-chip erase

There is a logic error in "whole chip erase" for the m25p80 family.  If
the whole device is successfully erased, erase_chip() will return 0, and
the code will fall through to the "else" clause, and do sector-by-sector
erase in addition to the whole-chip erase.  This patch corrects that.

Also, the MAX_READY_WAIT_COUNT is insufficient for an m25p16 connected
to a 400 MHz powerpc.  Increasing it allows me to successfully program
the device on my board.

Signed-off-by: Steven A. Falco <sfalco@harris.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/devices/m25p80.c

@@ -54,7 +54,7 @@
 #define	SR_SRWD			0x80	/* SR write protect */
 
 /* Define max times to check status register before we give up. */
-#define	MAX_READY_WAIT_COUNT	100000
+#define	MAX_READY_WAIT_COUNT	1000000
 #define	CMD_SIZE		4
 
 #ifdef CONFIG_M25PXX_USE_FAST_READ
@@ -246,10 +246,12 @@ static int m25p80_erase(struct mtd_info *mtd, struct erase_info *instr)
 	mutex_lock(&flash->lock);
 
 	/* whole-chip erase? */
-	if (len == flash->mtd.size && erase_chip(flash)) {
-		instr->state = MTD_ERASE_FAILED;
-		mutex_unlock(&flash->lock);
-		return -EIO;
+	if (len == flash->mtd.size) {
+		if (erase_chip(flash)) {
+			instr->state = MTD_ERASE_FAILED;
+			mutex_unlock(&flash->lock);
+			return -EIO;
+		}
 
 	/* REVISIT in some cases we could speed up erasing large regions
 	 * by using OPCODE_SE instead of OPCODE_BE_4K.  We may have set up