flash: fix typos and duplicated words

Fix typos and duplicated words in comments and strings.

Change-Id: I64282c7018462deefeeb8e5f4d0d81942425b3fc
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5758
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-by: Christopher Head <chead@zaber.com>

src/flash/nor/non_cfi.c

@@ -483,7 +483,7 @@ void cfi_fixup_non_cfi(struct flash_bank *bank)
 			break;
 	}
 
-	/* only fixup jedec flashs found in table */
+	/* only fixup jedec flashes found in table */
 	if (!non_cfi->mfr)
 		return;