staging: rts_pstor: dont cast void* from kmalloc()

 Casting (void *) value returned by kmalloc is useless
 as mentioned in Documentation/CodingStyle, Chap 14.

 The semantic patch that makes this output is available
 in scripts/coccinelle/api/alloc/drop_kmalloc_cast.cocci.

 More information about semantic patching is available at
 http://coccinelle.lip6.fr/Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/rts_pstor/rtsx_scsi.c

@@ -2730,7 +2730,7 @@ static int get_ms_information(struct scsi_cmnd *srb, struct rtsx_chip *chip)
 		buf_len = data_len = 0x6A;
 	}
 
-	buf = (u8 *)kmalloc(buf_len, GFP_KERNEL);
+	buf = kmalloc(buf_len, GFP_KERNEL);
 	if (!buf) {
 		TRACE_RET(chip, TRANSPORT_ERROR);
 	}