Fix all fo the bugs I introduced "improving" the code of others.

mmc_ll_cmds.c: mmc_mode_select and mmc_get_configuration now work.
mmc_hl_cmds.c: bug introduced by turning a var into a pointer to that variable.

lib/driver/mmc/mmc_cmd_helper.h

@@ -33,7 +33,6 @@
     if ( ! p_cdio ) return DRIVER_OP_UNINIT;				\
     if ( ! p_cdio->op.run_mmc_cmd ) return DRIVER_OP_UNSUPPORTED;	\
 									\
-    memset (p_buf, 0, i_size);						\
     CDIO_MMC_SET_COMMAND(cdb.field, mmc_cmd)				
 
 /* Boilerplate initialization code to setup running MMC read command

lib/driver/mmc/mmc_hl_cmds.c

@@ -83,7 +83,7 @@ mmc_get_disctype( const CdIo_t *p_cdio, unsigned int i_timeout_ms,
 	q = p+4;
 	*p_disctype = CDIO_MMC_DISCTYPE_NO_DISC;
 
-	while ((p_disctype == CDIO_MMC_DISCTYPE_NO_DISC) && 
+	while ((CDIO_MMC_DISCTYPE_NO_DISC == *p_disctype) && 
 	       (q < p + profiles_list_length)) {
 	    profile_number = CDIO_MMC_GET_LEN16(q);
 	    profile_active = q[2] & 0x01;

lib/driver/mmc/mmc_ll_cmds.c

@@ -74,9 +74,9 @@ mmc_get_configuration(const CdIo_t *p_cdio, void *p_buf,
 
 {
     MMC_CMD_SETUP(CDIO_MMC_GPCMD_GET_CONFIGURATION);
+    CDIO_MMC_SET_READ_LENGTH8(cdb.field, i_size);
     if (0 == i_timeout_ms) i_timeout_ms = mmc_timeout_ms;
     cdb.field[1] = return_type & 0x3;
-
     CDIO_MMC_SET_LEN16(cdb.field, 2, i_starting_feature_number);
     return MMC_RUN_CMD(SCSI_MMC_DATA_READ, i_timeout_ms);
 }
@@ -289,7 +289,6 @@ mmc_read_cd(const CdIo_t *p_cdio, void *p_buf1, lsn_t i_lsn,
 {
     void *p_buf = p_buf1;
     uint8_t cdb9 = 0;
-    const unsigned int i_size = i_blocksize * i_blocks;
     const unsigned int i_timeout = mmc_timeout_ms * (MAX_CD_READ_BLOCKS/2);
     
     MMC_CMD_SETUP(CDIO_MMC_GPCMD_READ_CD);