drivers/mtd/dataflash.c: Fix GCC 4.6 warning

Fix:
dataflash.c: In function 'AT91F_DataflashInit':
dataflash.c:42:6: warning: variable 'last_part' set but not used
[-Wunused-but-set-variable]

Signed-off-by: Anatolij Gustschin <agust@denx.de>
diff --git a/drivers/mtd/dataflash.c b/drivers/mtd/dataflash.c
index 96cd395..981ccd5 100644
--- a/drivers/mtd/dataflash.c
+++ b/drivers/mtd/dataflash.c
@@ -39,7 +39,6 @@
 	int i, j;
 	int dfcode;
 	int part;
-	int last_part;
 	int found[CONFIG_SYS_MAX_DATAFLASH_BANKS];
 	unsigned char protected;
 
@@ -136,7 +135,6 @@
 				dataflash_info[i].Device.pages_size) - 1;
 
 		part = 0;
-		last_part = 0;
 		/* set the area addresses */
 		for(j = 0; j < NB_DATAFLASH_AREA; j++) {
 			if(found[i]!=0) {
@@ -147,7 +145,6 @@
 					dataflash_info[i].Device.area_list[j].end =
 						dataflash_info[i].end_address +
 						dataflash_info[i].logical_address;
-					last_part = 1;
 				} else {
 					dataflash_info[i].Device.area_list[j].end =
 						area_list[part].end +