mmc: kconfig: replace FAULT_INJECTION with FAULT_INJECTION_DEBUG_FS

Fault-injection capability for MMC IO uses debugfs entries to configure
the attributes.
FAULT_INJECTION_DEBUG_FS must be enabled to use FAIL_MMC_REQUEST.

Replace FAULT_INJECTION with FAULT_INJECTION_DEBUG_FS.
Also remove 'select DEBUG_FS' since FAULT_INJECTION_DEBUG_FS depends on
it.
Signed-off-by: Adrien Schildknecht <adrien+dev@schischi.me>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

lib/Kconfig.debug

@@ -1523,8 +1523,7 @@ config FAIL_IO_TIMEOUT
 
 config FAIL_MMC_REQUEST
 	bool "Fault-injection capability for MMC IO"
-	select DEBUG_FS
-	depends on FAULT_INJECTION && MMC
+	depends on FAULT_INJECTION_DEBUG_FS && MMC
 	help
 	  Provide fault-injection capability for MMC IO.
 	  This will make the mmc core return data errors. This is