ZFS: Fix compile warning in cmd_zfs.c (GCC 4.6.4 from ELDK 5.2.1)

This patch fixes the following compile warnings:

cmd_zfs.c:177:1: warning: initialization from incompatible pointer type [enabled by default]
cmd_zfs.c:177:1: warning: (near initialization for '_u_boot_list_cmd_zfsls.cmd') [enabled by default]
cmd_zfs.c:182:1: warning: initialization from incompatible pointer type [enabled by default]
cmd_zfs.c:182:1: warning: (near initialization for '_u_boot_list_cmd_zfsload.cmd') [enabled by default]

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Jorgen Lundman <lundman@lundman.net>

common/cmd_zfs.c

@@ -46,7 +46,7 @@
 #define DOS_FS_TYPE_OFFSET	0x36
 #define DOS_FS32_TYPE_OFFSET	0x52
 
-static int do_zfs_load(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+static int do_zfs_load(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	char *filename = NULL;
 	int dev;
@@ -146,7 +146,7 @@ int zfs_print(const char *entry, const struct zfs_dirhook_info *data)
 
 
 
-static int do_zfs_ls(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+static int do_zfs_ls(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	const char *filename = "/";
 	int part;