staging: exfat: Fix a typo in Kconfig

This patch fix a spelling typo in Kconfig.
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Link: https://lore.kernel.org/r/20190930130504.21994-1-standby24x7@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/exfat/Kconfig

@@ -7,7 +7,7 @@ config EXFAT_FS
 	  This adds support for the exFAT file system.
 
 config EXFAT_DONT_MOUNT_VFAT
-	bool "Prohibit mounting of fat/vfat filesysems by exFAT"
+	bool "Prohibit mounting of fat/vfat filesystems by exFAT"
 	depends on EXFAT_FS
 	default y
 	help