Make SST49lf040 not clog the serial line too

Corresponding to flashrom svn r48 and coreboot v2 svn r2210.
diff --git a/sst49lf040.c b/sst49lf040.c
index 377b74f..641521a 100644
--- a/sst49lf040.c
+++ b/sst49lf040.c
@@ -60,10 +60,13 @@
 		erase_sector_jedec(bios, i * page_size);
 
 		/* write to the sector */
-		printf("%04d at address: 0x%08x ", i, i * page_size);
+		if(i&0xfff==0xfff)
+			printf("%04d at address: 0x%08x ", i, i * page_size);
+		
 		write_sector_jedec(bios, buf + i * page_size,
 				   bios + i * page_size, page_size);
-		printf("\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b");
+		if(i&0xfff==0xfff)
+			printf("\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b");
 		fflush(stdout);
 	}
 	printf("\n");