Revert "mmc: block: don't use parameter prefix if built as module"

This reverts commit 829b6962.

Revert this change as it causes a sysfs path to change and therefore
introduces and ABI regression. More precisely Android's vold is not being
able to access /sys/module/mmcblk/parameters/perdev_minors any more, since
the path becomes changed to: "/sys/module/mmc_block/..."

Fixes: 829b6962 ("mmc: block: don't use parameter prefix if built as
module")
Reported-by: John Stultz <john.stultz@linaro.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/card/block.c

@@ -47,13 +47,10 @@
 #include "queue.h"
 
 MODULE_ALIAS("mmc:block");
-
-#ifdef KERNEL
 #ifdef MODULE_PARAM_PREFIX
 #undef MODULE_PARAM_PREFIX
 #endif
 #define MODULE_PARAM_PREFIX "mmcblk."
-#endif
 
 #define INAND_CMD38_ARG_EXT_CSD  113
 #define INAND_CMD38_ARG_ERASE    0x00