fix building when saveenv is disabled in some setups

If you enable environment in the flash, but disable the embedded
option, and you disable the saveenv command, then the #if nested
logic will trigger a compile failure:
env_flash.c: In function 'env_relocate_spec':
env_flash.c:399: error: 'flash_addr' undeclared (first use in this function)
The fix is to add CMD_SAVEENV ifdef protection like everywhere else.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/common/env_flash.c b/common/env_flash.c
index eccfb62..a92160d 100644
--- a/common/env_flash.c
+++ b/common/env_flash.c
@@ -378,7 +378,9 @@
 		puts ("*** Warning - some problems detected "
 		      "reading environment; recovered successfully\n\n");
 #endif /* CFG_ENV_ADDR_REDUND */
+#ifdef CMD_SAVEENV
 	memcpy (env_ptr, (void*)flash_addr, CFG_ENV_SIZE);
+#endif
 #endif /* ! ENV_IS_EMBEDDED || CFG_ENV_ADDR_REDUND */
 }