part: fix "part list ... -bootable varname" to use hex

Unfortunately U-Boot assumes that almost all numbers are in hex, including
partition numbers passed to e.g. "load". So, the command "part list mmc 0
-bootable devplist" should use hex when writing partition numbers into
$devplist, so they'll be correctly interpreted.

Change-Id: I9a70b19749643876baadb45efbc3decaef8bfee2
Fixes: 0798d6fd ("part: Add support for list filtering on bootable partitions")
Cc: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>

common/cmd_part.c

@@ -100,7 +100,7 @@ static int do_part_list(int argc, char * const argv[])
 			if (bootable && !info.bootable)
 				continue;
 
-			sprintf(t, "%s%d", str[0] ? " " : "", p);
+			sprintf(t, "%s%x", str[0] ? " " : "", p);
 			strcat(str, t);
 		}
 		setenv(var, str);