mtd: fix typos in ooblayout comment blocks

- "This functions return ..." -> "This function returns ..."
 - "I you want ..." -> "If you want ..."

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/mtdcore.c

@@ -1128,7 +1128,7 @@ EXPORT_SYMBOL_GPL(mtd_write_oob);
  * @oobecc: OOB region struct filled with the appropriate ECC position
  *	    information
  *
- * This functions return ECC section information in the OOB area. I you want
+ * This function returns ECC section information in the OOB area. If you want
  * to get all the ECC bytes information, then you should call
  * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
  *
@@ -1160,7 +1160,7 @@ EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
  * @oobfree: OOB region struct filled with the appropriate free position
  *	     information
  *
- * This functions return free bytes position in the OOB area. I you want
+ * This function returns free bytes position in the OOB area. If you want
  * to get all the free bytes information, then you should call
  * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
  *
@@ -1190,7 +1190,7 @@ EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
  * @iter: iterator function. Should be either mtd_ooblayout_free or
  *	  mtd_ooblayout_ecc depending on the region type you're searching for
  *
- * This functions returns the section id and oobregion information of a
+ * This function returns the section id and oobregion information of a
  * specific byte. For example, say you want to know where the 4th ECC byte is
  * stored, you'll use:
  *